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3D FE Analysis of Flexible Pavement

3D FE Analysis of Flexible Pavement with Geosynthetic Reinforcement

Bassam Saad 1;Hani Mitri 2;and Hormoz Poorooshasb 3

Abstract:A series of ?nite element ?FE ?simulations are carried out to evaluate the bene?ts of integrating a high modulus geosynthetic into the pavement foundation.The simulations are conducted under a parametric study to investigate the bene?cial effects of geosynthetic reinforcement to the fatigue and rutting strain criteria,and to determine how such effects are in?uenced by the base quality and thickness as well as the subgrade quality.Three locations of the geosynthetic reinforcement are studied,namely the base–asphalt concrete interface,the base–subgrade interface,and inside the base layer at a height of 1/3of its thickness from the bottom.It is found that placing the geosynthetic reinforcement at the base–asphalt concrete interface leads to the highest reduction of the fatigue strain ?46–48%?.The placement of geosynthetic reinforcement in thin bases is particularly effective;the highest decrease of rutting strain ?16–34%?occurs when the reinforcement is placed at a height of 1/3of the base thickness from the bottom.The study is carried out with the ?nite element program ADINA using a three-dimensional ?3D ?dynamic modeling technique with implicit solution scheme.DOI:10.1061/?ASCE ?0733-947X ?2006?132:5?402?

CE Database subject headings:Finite element method;Dynamic analysis;Flexible pavements;Elastoplasticity;Geosynthetics;Reinforcement .

Introduction

Prolonging the service life of a pavement system and thus reduc-ing the life-cycle cost is a fundamental objective of pavement designers.In the last three decades,the geosynthetic reinforce-ments ?high modulus geosynthetics such as the polymeric geo-grid ?have been increasingly utilized to improve the structural performance of both newly constructed and rehabilitated pave-ment systems to achieve such objective.The wide use of the geosynthetic reinforcement in roads has motivated several pave-ment agencies and universities to conduct research work on this material and integrate it in the design methods of conventional pavement systems.

A recent release of the American Association of Highway and Transportation Of?cials ?AASHTO 2001?provides a recom-mended practice guide for geosynthetic reinforcement incorpor-ation in the ?exible pavement system.However,such a guide is not intended for addressing the structural bene?ts offered by the addition of a geosynthetic reinforcement layer.Evaluating the bene?ts added to the ?exible pavement system as a consequence

of using the reinforcement geosynthetic has been the objective of several new research projects,which have been initiated in the United States ?Maine DOT 2002;CRREL 2003?.In addition,the Federal Highway Administration ?FHwA ?,European road agencies,and some reinforcement manufacturers are currently co-sponsoring a research project to reach methods for incorporation of reinforcement products in ?exible pavements.The FHwA and these agencies are interested in seeing these methods compatible with the mechanistic-empirical approaches ?ISAP 2002?.

Deciding the conditions under which the geosynthetic reinforcement is bene?cial and the bene?ts added to the pavement structure as a result of its utilization is dependent on:?1?the parameters of the pavement layers to be reinforced;?2?the char-acteristics of the geosynthetic reinforcement being used;?3?the location of geosynthetic within the pavement system;and ?4?the features of the traf?c loading which affect such a system.

The purpose of this paper is to investigate the bene?ts provided by geosynthetic reinforcement to the fatigue and rutting resistances of a ?exible pavement system under different condi-tions of its foundation.The effect of geosynthetic location within the granular base layer is also explored in this study.

The fatigue resistance of the pavement system is evaluated through the maximum tensile strain transmitted to the bottom of the asphalt concrete layer ??t max ?whereas the maximum compres-sive strain transmitted to the top of subgrade ??c max ?is used in conjunction with the maximum vertical surface de?ection to evaluate the rutting resistance of the pavement.Fig.1illustrates the locations of such strain components in a conventional ?exible pavement system.

The impacts of the foundation parameters ?base thickness,base quality,and subgrade quality ?and the location of the rein-forcement on the performance of the reinforced pavement system 1Ph.D.Student,Dept.of Mining,Metals and Materials Engineering,McGill Univ.,3450University St.,Montreal PQ,Canada H3A 2A7;formerly,M.Eng.Student,Concordia Univ.,Montreal PQ,Canada H3A 1M8.2

Professor,Dept.of Mining,Metals and Materials Engineering,McGill Univ.,3450University St.,Montreal PQ,Canada H3A 2A7?corresponding author ?.E-mail:hani.mitri@mcgill.ca 3

Professor,Dept.of Building,Civil and Environmental Engineering,Concordia Univ.,1257Guy St.,Montreal PQ,Canada H3G 1M8.

Note.Discussion open until October 1,2006.Separate discussions must be submitted for individual papers.To extend the closing date by one month,a written request must be ?led with the ASCE Managing Editor.The manuscript for this paper was submitted for review and pos-sible publication on October 20,2003;approved on July 6,2005.This D o w n l o a d e d f r o m a s c e l i b r a r y .o r g b y T i a n j i n U n i v e r s i t y o n 12/21/14. C o p y r i g h t A S C E . F o r p e r s o n a l u s e o n l y ; a l l r i g h t s r e s e r v e d .

Literature Review

The potential for the geosynthetic reinforcement to enhance the structural performance of paved roads was examined by pavement researchers through laboratory,?eld,and numerical modeling investigations.The improvement to the pavement system provided by geosynthetic reinforcement can be directly measured by a traf?c bene?t ratio ?TBR ?,which is de?ned by Berg et al.?2000?as follows:“A ratio of the number of load cycles on a reinforced section to reach a de?ned failure state to the number of load cycles on an unreinforced section,with the same geometry and material constituents,to reach the same de?ned failure state.”

The laboratory experiments of Haas ?1984?showed that reduc-tions of 30%in the maximum tensile strain transmitted to the bottom of the asphalt-concrete ?AC ?layer and 20–40%in the maximum vertical compressive stress at the top of subgrade occurred as a result of placing a polymeric grid at the bottom of the AC layers of different thicknesses.The in?uence of the granular base on the performance of the reinforced section was not included.The results of another test program conducted by Haas et al.?1988?showed that the base thickness could be re-duced by about 25–50%as a result of using the geogrid.The optimum depth was found to be dependent on the granular base layer and the subgrade strength.After the ?rst 10,000load cycles ?when a membrane effect has not been developed signi?cantly,and the interlocking mechanism is predominant ?,the rut depth decreases from 20.3mm ?0.8in.?for the unreinforced system to 11.6mm ?0.46in.?for the reinforced system.Such a reduction was higher for weaker subgrade.It was concluded that the best location can be chosen by using stress-strain analysis such that the radial strain under the load center at the proposed grid location should be within some limiting range between 0.05and 0.2%.Checking the strength against pull out is not required in this case.In addition,a grid placed at the midpoint of a 304.8mm ?12in.?thick base layer does not show any bene?ts until large deformations take place.

Haas et al.?1988?did not consider the effects of AC and base moduli on the performance of a geogrid-reinforced pavement Miura et al.?1988?carried out comprehensive laboratory investigations on the role of the geosynthetic membrane rein-forcement in pavements.The surface settlement was taken as a comparison criterion between reinforced and unreinforced sections.They concluded that:?1?when placing the grid at the base–subgrade interface,the magnitude of the tensile strain in the geogrid is maximum at the center of a loading test plate;?2?the induced tensile stress in a grid with a higher modulus is higher than that of a grid with a lower modulus,and the geogrid contrib-utes more effectively to suppress the surface rutting;and ?3?if the grid is placed at the bottom of the AC layer,the performance of the asphalt pavement improves if strong bonding is maintained between the AC layer and the geogrid.Further improvement is obtained in the case of dynamic loading.

Special laboratory tests were done by Chang et al.?1988?to evaluate the resistance of a geogrid reinforced asphalt-concrete ?AC ?beam to fatigue cracks.The geogrid was laid at 1/3of the thickness of the specimen from the bottom surface.The failure criterion was de?ned when the crack grew throughout the entire cross section of the beam,which was placed on a rubber mat idealizing the subgrade.The number of cycles to failure for the reinforced beam was much greater than for the unreinforced one under different levels of loading.Such an increase in the number of cycles was dependent on the magnitude of the applied load.In addition,the surface settlement was also reduced compared to the reference unreinforced system,and such reduction in the number of cycles for reaching a speci?c settlement was also dependent on the magnitude of the applied force.

Barksdale et al.?1989?found that for the stronger pavement,the stiff geogrid at the bottom of the granular base did not produce any signi?cant improvement.Their results indicated that placing the geogrid in the middle and bottom of the base,despite its lower stiffness,resulted in better performance against perm-anent deformation than the geotextile.This fact was highly pronounced for the ?rst 105load cycles.Permanent vertical deformation of the pavement was taken as a parameter to charac-terize the performance of the reinforced system compared to the unreinforced one.Permanent vertical strain,vertical resilient strain,and transient stresses were also analyzed.In their study Barksdale et al.?1989?also carried out ?nite element simulations to verify the results obtained in the laboratory.They used axisym-metric representation for the pavement system.Two material models were suggested for the base,the ?rst was a nonlinear isotropic elastic-plastic model,and the second was an elastic cross-anisotropic model.The geogrid was modeled by a mem-brane element.Their model showed that the geosynthetic bene?t is more pronounced for pavement with weak subgrade.It,how-ever,underestimated the vertical strain at the top of subgrade and overestimated the strain induced in the geosynthetic located at the bottom of the bases by 33%.

Dondi ?1994?used the commercial ?nite element program ABAQUS to model a geosynthetic reinforced ?exible pavement.Three-dimensional ?3D ?static analysis was used.The load was applied to re?ect a dual-wheel simulated by two rectangular areas representing the contact pressure of 1,500kPa.The CamClay and Drucker-Prager were used to simulate the subgrade and the granular base layers,respectively.The linear elastic material model was used for the asphalt concrete layer and the geosyn-thetic reinforcement.A four-node interface element following Coulomb friction behavior was used to model the geosynthetic interface with the surrounding soil materials.The results of their

Fig.1.Conventional ?exible pavement system showing the locations of fatigue and rutting strains ?t max and ?c max ,respectively,used as failure criteria

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vertical displacement of the loaded area was reduced by 15–20%in the reinforced section;and ?3?the fatigue life of the reinforced section increased by 2–2.5times compared to the unreinforced section.

Wathugala et al.?1998?used the ABAQUS ?nite element program to explore the decrease in the rut depth as a result of placing the geosynthetic membrane at the base–subgrade interface of a ?exible pavement system.The axisymmetric analysis was adopted in their simulations which introduced the hierarchical single surface ?HiSS ??Desai et al.1986;Wathugala and Desai 1993?model for subgrade.The asphalt concrete and the crushed stone base layers were modeled by Drucker-Prager material.No special interface models were used between the geogrid and the surrounding soil.The inclusion of the geogrid reduced the permanent rut depth by approximately 20%for a single cycle of load.

Nejad and Small ?1996?investigated the role of geogrid in a conventional pavement system and concluded that a remarkable reduction in the vertical surface deformation resulted from the interlocking function particularly in the vicinity of the reinforce-ment.In both single and multiple track tests performed,the small-est surface deformation was obtained with geogrid at the center of the base layer.

Berg et al.?2000?showed in their review that geosynthetic membrane used to reinforce pavements systems provides,under certain conditions,substantial load-carrying bene?ts to such systems.These conditions are controlled by subgrade strength,aggregate base characteristics,design requirements,and geosynthetic characteristics.

Perkins ?2001?tested three different locations of the geogrid,while varying its stiffness,base thickness,and the subgrade strength.For a weak subgrade,the surface de?ection was reduced by 50%at 10,000load cycles when it was placed at the middle of the base;this reduction was noticed to continue with increasing the number of cycles.The geogrid with a higher stiffness gave better traf?c bene?ts ratio ?TBR ?.In addition,the increase in TBR when the geogrid was placed in the middle was higher than the value obtained when the same geogrid was placed at the base–subgrade interface.When the rut depth becomes more than 10mm,the geogrid in the system with a thicker base produced higher TBR than the system with a thinner base.The effect of the geogrid and its location on the fatigue life ?maximum tensile strain at the bottom of the AC layer ?of the pavement,the quality of the base,and AC layers were not examined in the study.

In his ?nite element simulations,Perkins ?2001?performed a 3D analysis to duplicate the case of a test box.A Coulomb friction model was used to describe the interaction between the geosyn-thetic reinforcement and the base aggregate layer.The AC was modeled by an anisotropic elastic-perfectly plastic model.A boundary surface plasticity model was used for both the subgrade and the aggregate materials.The results indicated the importance of the shear stress transmitted to the subgrade.The many models suggested by Perkins which included another set of interface elements between the geogrid and underlying subgrade did not give the anticipated results.The same dif?culties were encoun-tered when the geogrid was placed within the base.Perkins stated that these cases required improvements in the base aggregate model to account for the effects of the reinforcement.The tensile strain at the bottom of the AC layer ?fatigue criterion ?,and the In their laboratory study,Ling and Liu ?2001?placed the geogrid between the AC layer and Ottawa sand.For cyclic load-ing,the system reinforced with polypropylene which is able to achieve high interlocking with the surrounding medium showed strength three times higher than the strength of the unreinforced system.No debonding was noticed between the geogrid and AC layer when the system failed.In their ?nal remarks Ling and Liu ?2001?reported that pavement performance is improved if an effective bonding is maintained between the AC layer and the geogrid.More recently,Ling and Liu ?2003?used the two-dimensional commercial ?nite element program PLAXIS to model the laboratory test previously conducted on a geogrid re-inforced pavement system ?Ling and Liu 2001?.The AC layer and the subgrade underneath followed the elastoplastic Mohr-Coulomb failure criterion.The ?nite element analyses were per-formed under the plane strain condition.The geogrid was placed at the asphalt concrete–subgrade interface and was modeled by a linear elastic bar element.Ling and Liu ?2003?concluded that the associated and nonassociated rules gave similar results and the settlement pro?le for unreinforced and reinforced pavement systems compared favorably with the test results.In addition,the results showed that reinforcement effect was more pronounced for weaker subgrade foundation.Such effect increased as the strain level on the subgrade was increased.

Finite Element Model Considerations Three-Dimensional Analysis

The three-dimensional ?3D ?analysis is adopted in this study.Justi?cations for using 3D analysis to model a pavement system were elaborated by Hjelmstad et al.?1997?and Kim and Buttlar ?2002?.They can be summarized as follows:

1.It better re?ects the complex behavior of the composite

pavement system materials under traf?c loads of different con?gurations;

2.It is preferred when the veri?cation of the numerical model

results with the laboratory or ?eld test results is desired;and 3.It is capable of simulating the rectangular footprint of the

loaded wheel ?Yoder and Witczak 1975?.When dealing with two-dimensional analysis,the shape of the load surface is restricted to a circle ?axisymmetric condition ?or in?nite long strip ?plane strain condition ?,which are both not realistic.Loading System

A legal axle in most states ranges from 80kN ?18,000lb ?to 90kN ?20,000lb ??Yoder and Witczak 1975?.In this study,a load of one set of dual tires of 40kN ?9,000pounds ?is consid-ered.It is assumed that this load is transferred to the pavement surface through a contact pressure of a single tire.As the stiffen-ing effect of the tire wall is neglected,the tire contact pressure on the road is equal to the tire pressure,which is taken as 550kPa ?80psi ?.In the 3D analysis,the shape of the contact area could be a combination of a central rectangle with semicircles at the ends ?Yoder and Witczak 1975?with length calculated as

L =

0.5226

1/2

?1?

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The Center of Transportation Research investigated tire contact area versus wheel loading,and the average contact area under 40kN wheel load was reported to be between 64,520mm 2?100in.2?and 70,972mm 2?110in.2??Hansen et al.1989?.In the present analyses,the contact area of 72,585mm 2?9,000/80?112.5in.?is considered.Applying Eq.?1?to a single rectangular area with no semicircles at the ends,the contact area is converted into a rectangle with length L ?372.6mm ?14.67in.?and B ?194.7cm ?7.667in.?.For numerical modeling,these dimensions were taken as L ?406.4mm ?16in.?and B ?177.8mm ?7in.?.The layout of the contact area is shown in Fig.2?a ?.

For a given point in the pavement system,the effect of the wheel load passage at that point can be re?ected by a stress pulse ?Terrel et al.1974?.The magnitude,shape,and duration of such a pulse vary with the stiffness of pavement,wheel load magnitude,its speed,and the depth of the studied point.A triangular wave with a duration of 0.1s corresponding to an average speed of around ?32.18km/h ?20mph ?Barksdale 1971?with a peak load of 40kN is adopted in this study;see Fig.2?b ?.Boundary Conditions

Conventional kinematic boundary conditions are adopted,i.e.,roller support on all four vertical boundaries of the mesh and ?xed support at the bottom of the mesh.Such boundary conditions have been successfully used by Zaghloul and White ?1993?,and Kuo et al.?1995?.

Meshing Consideration and Dynamic Analysis

The modeled domain must be large enough to avoid any edge error.On the other hand,the mesh size should not be increased signi?cantly in order to keep the problem size manageable for computation time and storage requirements.Assuming that the road analyzed is subjected to low traf?c volume of moderate load value,a typical road cross section with the geometry shown in Fig.3is adopted.As the pavement system response to only a single wheel load is investigated,half of the system is invest-igated in the current study.In addition,the load is considered to be at the center of the road cross section for numerical modeling purposes.To achieve the objective of studying the base thickness in?uence on the performance of the geosynthetic-reinforced pave-ment system,two different thicknesses of the granular base layer are investigated,namely 152.4and 304.08mm;see Fig.3.

Due to the double symmetry of geometry,boundary cond-itions,and load about the horizontal x and y axes,only a quarter model is considered.The model is 2.5m wide and 3m long with depth changing according to thickness of the base layer;refer to Fig.4.A particularly stable and successful element,which is usually used in modeling the layers of a pavement system and employed in this study,is the eight-node isoparametric element with reduced integration scheme ?Cho et al.1996;Hjelmstad et al.1997?.

As the loading on the pavement surface is localized,the ?nest mesh is required near the loaded area to capture the step stress and strain gradient in these areas.The subdivision is carried out so that the element aspect ratio remains close to one where the strain and stress gradients are high to achieve faster convergence in these areas.The distributed wheel load is applied to an integer number of elements.

The geosynthetic reinforcement is modeled with a four-node membrane element.The four-node membrane element in ADINA is a 3D isoparametric,plane stress displacement-based element,which can lie in three-dimensional space ?Fig.5?.This element allows only for in-plane stresses and does not take any bending nor compression stresses.The ?nite element formulations of this element are described in detail by Bathe ?1996?.

The AC and subgrade are modeled with 720and 2,160eight-node isoparametric elements,respectively.The number of eight-node isoparametric elements modeling the granular

base

Fig.2.Traf?c load of a single tire:?a ?tire contact area modeled and ?b ?load-time

function

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varies according to the base thickness,namely 1,800elements for the thick base ?304.8mm ?,and 1,080elements for the thin base ?152.4mm ?.The selected 3D ?nite element mesh is shown in Fig.6.

The implicit direct integration method,which is convenient for time history analysis,is selected to numerically handle the solution of the dynamic equilibrium equations sets of pavement systems analyzed.The selection was based on the following reasons ?Cook et al.1989?.

1.The implicit method is suited to structural dynamics prob-lems;it competes with the modal superposition method,and it may be cheaper where many modes would be needed in the modal analysis;

2.It is unconditionally stable and the size of time step,?t ,

in contrast with the explicit method,is limited only by con-sideration of the accuracy rather than the numerical stability.In the present study,the triangular load wave of duration of 0.1s ?Fig.2?b ??has been divided into 20time steps;and 3.Nonlinearity can be accommodated without great trouble.

Materials Behavior and Constitutive Laws Asphalt Concrete Layer

The contribution of the AC layer to surface rutting is dependent on the material properties of the system layers.Harold ?1994?indicated that the AC layer behaves elastic or viscoelastic at low temperature ?the plastic response of bituminous mixtures can be neglected ?.Also,Benedetto and La Roche ?1998?concluded that bituminous mixtures exhibit a complex elastoviscoplastic response but at small strain magnitude the plastic component can be neglected.In this study,where the AC properties are consid-ered at low temperature and for the given load amplitude,the vertical permanent deformation of the AC layer is considered to have insigni?cant contribution to the total surface de?ection.Furthermore,for a load affecting a structure,when the time duration of this load is small,which is the case beforehand,the viscoelastic behavior of this structure becomes almost equivalent considered a reasonable assumption in view of the asphalt properties and characteristics of the loading system ?relatively short time duration and amplitude of the wave re?ecting the traf?c load ?adopted.Granular Base Materials

Elastoplastic models like Drucker–Prager and Mohr–Coulomb are considered the simplest models,which could represent the elastoplastic soil and granular material behavior.In addition to their capacities to simulate the nontensioning behavior and the hydrostatic sensitivity response exhibited by the granular

ma-

Fig.4.3D ?nite element model

geometry

Fig. 5.Four-node membrane element shown in the X -Y plane ?note:d 3,d 6,d 9,and d 12=out of plane degrees of freedom

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terials,such models re?ect some other important characteristics of the granular material such as elastic response at lower stress level and plastic response at higher stress level,small material stiffness near failure,failure condition,and elastic unloading after yielding ?Baladi and Chen 1985?.The Drucker-Prager is easier to handle numerically than Mohr-Coulomb,as convergence dif?culty arises at the vertices of Mohr-Coulomb yield surface where the associative plasticity rule is not met.The Drucker-Prager yield function in the p -q plane is shown in Fig.7?a ?.With granular materials having zero cohesion,only the internal friction angle is required to characterize a Drucker-Prager unbound granular material.Subgrade

The subgrade is simulated by the modi?ed CamClay model ?Desai and Siriwardane 1984?,which is developed from the critical state concept ?Scho?eld and Wroth 1968?.The CamClay model in the program ADINA ?Adina R&D 2001?is based on the following considerations:

1.An associated ?ow rule using an elliptical yield function and

isotropic hardening rule,see Fig.7?b ?;

2.The critical void line or “the critical state line,”as renamed

by Poorooshasb ?1961?,which controls the failure of the material;and

3.The consolidation behavior of the clayey materials.

The CamClay can simulate the strain hardening and softening under normal consolidation or overconsolidation states and the nonlinear dependence of the elastic volumetric strain on the hydrostatic pressure.It also re?ects the ultimate condition of Geosynthetic Reinforcement

Perkins ?2001?conducted a literature review showing the consti-tutive laws implemented in previous ?nite element analyses of geosynthetic reinforced ?exible pavement systems.In his review,Perkins ?2001?demonstrated that in most of these analyses the geosynthetic reinforcement membrane is considered as an isotro-pic elastic material.A model including components of plasticity,creep,and directional dependency of the high modulus geosyn-thetic ?polymeric geogrid ?would be more realistic.However,such a model is considered oversimpli?ed and not practical for use in the numerical simulations because it requires many param-eters,which are not de?ned in the existing manuals produced by the manufacturers.Therefore in this study the geogrid is assumed to act as a linear isotropic elastic material.Such model proved ef?cient when used by other researchers;e.g.,Dondi ?1994?;and Ling and Liu ?2003?.As the membrane element does not take out of plane shear,?xz =?zy =0,the strains induced within the element can be obtained from the following equation:

??xx ?yy ?zz ?xy

1/E ??/E 0

0??/E 1/E 0

0??/E ??/E 0

0000?1+??/E

???xx ?yy 0?xy

?2?

It is assumed that no slippage occurs between the material layers.The full bonding of the geosynthetic and the surrounding layers is an acceptable assumption for the case of a paved system where the allowed surface rutting of such a system surface is small and the slippage is not likely to occur unless excessive rutting takes place ?Barksdale 1989;Espinoza 1994?.It is also worth-

Fig.7.Illustration of constitutive models used for modeling the base and subgrade materials:?a ?Drucker–Prager and ?b ?CamClay

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fabric and surrounding layers,has limitations in modeling the real problem and misleading results have been reported concerning these coef?cients ?Palmeira and Milligan 1989?.Furthermore,in their state-of-the-art report on pullout and direct shear testing of geosynthetic reinforcement,Mallick et al.?1996?concluded that there is a large discrepancy in the data obtained from the pullout test results.

Model Features and Limitations

To summarize,the ?nite element modeling technique adopted in this study has a number of interesting features,which when combined,makes it unique and different from those previously reported in the literature.The following points highlight the model features.

?Three-dimensional,dynamic analysis;

?The base is treated as an elastoplastic Drucker–Prager mate-rial;

?The subgrade is simulated by the Modi?ed CamClay model;?The dynamic load is simulated with a triangular wave having a duration of 0.1s;and

?The geosynthetic reinforcement is modeled as a membrane element.

On the other hand,the inherent assumptions of the current model are

?The asphalt concrete layer is treated as linear elastic;

?The geosynthetic reinforcement is treated as linear elastic material;and

?Perfect bonding ?no slippage ?is assumed at the interface between the geosynthetic reinforcement and the surrounding foundation layers.

Finite Element Model Parametric Study

Studying the performance of the geosynthetic-reinforced pave-ment system and its variation with the geosynthetic location is conducted through a parametric study.The major goal of such a study is to capture the impacts of the foundation parameters re?ected by granular base thickness,granular base quality,and subgrade quality,as well as the geosynthetic location on the structural performance of ?exible pavement systems.

Studying the effects of the base thickness is done through modeling two thicknesses.These are 152.4mm ?6in.?and 304.8mm ?12in.?.The effect of granular base quality is examined by testing two types of base materials,namely,weak pavement response,namely clay and silty sand subgrade.Three locations of the geosynthetic reinforcement are studied as shown in Fig.8.

To achieve the parametric study,the impacts of the geosyn-thetic reinforcement on six different pavement systems are investigated.The systems analyzed are varying according to the foundations parameter as demonstrated in Table 1.For each system the pavement foundation consists of an elastoplastic Drucker–Prager base resting on an elastoplastic strain hardening CamClay subgrade.The foundation materials data required for the adopted constitutive laws are taken from previously published literature,see Table 2.On the other hand,the geosynthetic rein-forcement and the asphalt-concrete ?AC ?layers are considered linear elastic and their inputs are kept constant in all analyses,see Table 3.

For each system,four sections,which vary according to the geosynthetic reinforcement existence and location,are analyzed as illustrated in Fig.8.Consequently,24pavement sections are examined through ?nite element simulations so that the effect of each of the aforementioned factors on the performance of each geosynthetic-conventional ?exible pavement system is explored,and the interactions between such factors are understood.

Results and Discussions

The fatigue and rutting strains,?t max and ?c max ,evaluated,respectively,at Elements A and C,are reported in Table 4for each section analyzed;refer to Fig.9.Additionally,the plots of ?1?horizontal strain transmitted along the bottom edge of the AC layer,Edge ?3-4?shown in Fig.9,and considered at the peak load time and ?2?vertical surface de?ection predicted along Edge ?1-2?shown in Fig.9,and considered at the peak load time,are presented in Figs.10–15for the sections analyzed.

Table 1.De?nition of Pavement Systems Analyzed

System Subgrade quality Base

Quality Thickness ?mm ?in.??1Clay Weak 304.8?12?2Clay Strong 304.8?12?3Silty sand Weak 304.8?12?4Clay Weak 152.4?6?

Fig.8.Locations of the geogrid adopted in the parametric study for each pavement system analyzed:?a ?unreinforced;?b ?AC-base interface;?c ?lower third of the base:and ?d ?base-subgrade interface ?refer to Table 2?

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About the Fatigue Strain Criterion

It is seen from Table 4that the geosynthetic placed at the bottom of the AC layer leads to the highest reduction of ?t max .Such a reduction,which reaches 48%in the pavement of weak foundation,is almost independent of the base thickness and foun-dation quality.Figs.10–15show that the reduction in horizontal strain transmitted to the bottom of the AC layer and considered at peak load is maximum at the node having maximum horizontal tensile strain.

It is also noticed from results reported for thick base systems that ?t

max decreases slightly when placing the geosynthetic at the bottom of the base and at 1/3of its thickness from the bottom.Figs.10?a ?,11?a ?,and 12?a ?also show that the geosynthetic reinforcement placed at such locations has negligible in?uence on the horizontal strain transmitted to the bottom of the AC layer and considered at peak load time.On the other hand,for systems having a thin granular base layer,the geosynthetic reinforcement placed at 1/3of the base thickness shows remarkable decrease of ?t

max value and such a decrease is dependent on the foundation quality.As can be seen from Table 4,the decrease in the value of ?t

max which reaches to 33%is more pronounced when having clayey subgrade and thick base.Figs.13?a ?,14?a ?,and 15?a ?indicate that geosynthetic reinforcement gives higher reduction in the areas having high stress intensity.The highest reduction in the horizontal strain is obtained for the wheel load center node,which has the highest value of the tensile strain.The reduction becomes less pronounced when going far from this node along the hori-zontal surface until it vanishes when the tensile strain becomes negligible or vanishes at a distance of almost 170–200mm from the wheel load center.

It can be concluded from these observations,which concern the fatigue criterion,that the maximum decrease in ?t

max occurs when placing the geosynthetic reinforcement at the bottom of the AC layer and such decrease tends to be independent of the base quality,subgrade quality,and base thickness.The geosynthetic reinforcement in this case signi?cantly participates in absorbing the horizontal tensile strain induced at the bottom of the AC layer,which would be otherwise carried by the AC alone.As a result,the overall performance of the asphalt pavement is improved if the effective bonding is maintained between the geogrid and AC.This agrees well with the conclusion of Ling and Liu ?2001?.Moreover,the value of ?t

max decreases only slightly when the results of the simulations conducted on the thin base systems,show that placing geosynthetic at the lower third of the base still lead to a tangible decrease in ?t max ;such a decrease is more pronounced when using a stronger base.In addition,when reinforcing a weak base,the decrease in ?t

max obtained with the placement of geosynthetic reinforcement is more pronounced in the case of founding on clayey subgrade.About the Rutting Strain Criterion and Vertical Surface De?ection

With respect to systems having thick bases,the results reported for weak base systems,demonstrate that the ideal location of the geosynthetic reinforcement for decreasing ?c

max is at the top of the base ?the reduction of ?c max

is 11%?.However,when the base is strong,the best location of the geosynthetic reinforcement to reduce ?c max is at the base–subgrade interface ?the reduction of ?c max

is 14%?.Such observations also indicate that subgrade qual-ity does not appear to in?uence the decrease of ?c

max obtained as a result of integrating the geosynthetic reinforcement in a pavement system having a thick base.Figs.10?b ?,11?b ?,and 12?b ?show that there is no material reduction in vertical surface de?ection predicted as a result of using the geosynthetic reinforcement for supporting the pavement systems of the thick base.

For thin base systems,placing the geosynthetic reinforcement at 1/3of the base thickness from the bottom leads to a signi?cant reduction in ?c

max ?16–34%?with the largest reduction ?34%?in the case of the weak ?clay ?subgrade.

Figs.13?b ?,14?b ?,and 15?b ?show how vertical surface de?ec-tion predicted along the Edge ?1-2??Fig.9?and considered at the peak load decreases along such an edge as a consequence of placing the geosynthetic reinforcement at the lower third of base thickness from the bottom.Such reduction reaches its peak

Table 2.Characteristics of Pavement Foundation Layers Adopted for Model Parametric Study

Data

and source Subgrade layer

Base layer

Modi?ed CamClay model

Elastoplastic ?Drucker–Prager ?model Clay

Silty sand

Weak base Strong base Data

E =8,280kPa E =50,646kPa

E =96,793kPa

E =414,000kPa

?=0.25?=0.28?=0.3?=0.3M =1M =1.24??*?=25°

?=38°

?=2.1?=1.347k =0.026k =0.0024?=0.147?=0.014OCR ?1OCR ?1e 0=1.08

e 0=0.34

Source Desai and Siriwardane ?1984?

Desai and Siriwardane ?1984?

Liu et al.?1998?a

Zaghloul and White ?1993?

Assumed.

Table 3.Mechanical Properties of Asphalt Concrete and Geosynthetic Reinforcement

Material Young modulus E ?kPa ?Poisson’s ratio ?Source

Asphalt-concrete 4,134,6930.30Zaghloul and White

?1993?

D o w n l o a d e d f r o m a s c e l i b r a r y .o r g b y T i a n j i n U n i v e r s i t y o n 12/21/14. C o p y r i g h t A S C

E .

F o r p e r s o n a l u s e o n l y ; a l l r i g h t s r e s e r v e d .

immediately under the wheel load center where the increase in the pavement system stiffness reaches its maximum ?almost 35%?.The difference in surface de?ection ?taken as an absolute value ?between the reinforced systems and unreinforced systems tends to decrease by moving along the edge away from the wheel load center until it disappears completely at a distance of 1,100mm from the wheel load center.The graphs also show that the

pavement systems reinforced in these situations have a ?atter pro-?le of vertical surface de?ection than the unreinforced systems.It is concluded from the above results and observations regard-ing the rutting strain criterion that the geosynthetic potential of decreasing ?c

max is much more pronounced when using it in the systems having thin bases of 152.4mm ?6in.?than when it is used in the thick bases of 304.8mm thick.For systems having a thick base,the range of ??c max ?decrease obtained is 11–15%.The results show little effect of the base quality and negligible in?uence of subgrade quality on the decrease of ??c max ?value.For the case of weak bases systems,the ideal location for decreasing

max was at the top of the base layer.However,for systems having the strong bases,the geosynthetic reinforcement placed at the base–subgrade interface gives the best results in terms of rutting strain criterion.

Comparison of Results Trend with Analyses Observations Reported in the Literature

The writers have qualitatively compared the results obtained from this study with the results of investigations summarized earlier under the literature review section of this paper and found that fairly good agreement is obtained concerning the observations:?1?the reinforcement effect is more pronounced for weaker subgrade foundation,refer to Barksdale et al.?1989?and Ling and Liu ?2003?;?2?under moderate load the geosynthetic appears to be more bene?cial when the base is thin,refer to Berg Table 4.FE Predicted Fatigue and Rutting Strains Criteria Pavement foundation

Geosynthetic location in base ??t max ?·E?4??c max ?·E?3

??t max ???c max ?

Weak thick base over clayey subgrade

N/A

3.35?3.13

—

—Bottom of base 3.34?3.000.24Lower 1/3of base 3.28?3.252?3Top of base 1.75?2.774811Strong thick base over clayey subgrade

N/A

2.32?2.17——Bottom of base 2.20?1.86414Lower 1/3of base 2.15?2.0078Top of base 1.28?2.00448Weak thick base over silty sand subgrade

N/A

3.33?1.24——Bottom of base 3.33?1.220.091Lower 1/3of base 3.27?1.33 1.8?6Top of base 1.74?1.104711Weak thin base over clayey subgrade

N/A

3.73?3.88——Bottom of base 3.61?3.77 3.23Lower 1/3of base 2.89?2.932224Top of base 1.93?3.344814Strong thin base over clayey subgrade

N/A

3.21?3.25——Bottom of base 2.65?2.761715Lower 1/3of base 2.14?2.133334Top of base 1.71?2.884611Weak thin base over silty sand subgrade

N/A

3.46?1.67——Bottom of base 3.40?1.6422Lower 1/3of base 2.86?1.391716Top of base

1.80

?1.45

Note:N/A ?not

available.

Fig.9.Locations observed in the ?nite element simulations:?a ?horizontal microstrain predicted along the bottom of the AC D o w n l o a d e d f r o m a s c e l i b r a r y .o r g b y T i a n j i n U n i v e r s i t y o n 12/21/14. C o p y r i g h t A S C E . F o r p e r s o n a l u s e o n l y ; a l l r i g h t s r e s e r v e d .

Fig.10.Dynamic response considered at the peak load time of the pavement system having weak thick base and clayey subgrade:?a ?horizontal microstrain predicted along the bottom of the AC layer ?Edge ?3-4?in Fig.9?and ?b ?vertical surface de?ection predicted along Edge ?1-2??de?ned in Fig.9

Fig.11.Dynamic response considered at the peak load time of the pavement system having strong thick base and clayey subgrade:?a ?horizontal D o w n l o a d e d f r o m a s c e l i b r a r y .o r g b y T i a n j i n U n i v e r s i t y o n 12/21/14. C o p y r i g h t A S C E . F o r p e r s o n a l u s e o n l y ; a l l r i g h t s r e s e r v e d .

Fig.12.Dynamic response considered at the peak load time of pavement system having weak thick base and silty sand subgrade:?a ?horizontal microstrain predicted along the bottom of the AC layer ?Edge ?3-4?in Fig.9?and ?b ?vertical surface de?ection predicted along Edge ?1-2??de?ned in Fig.9

Fig.13.Dynamic response considered at the peak load time of pavement system having weak thin base and clayey subgrade:?a ?horizontal D o w n l o a d e d f r o m a s c e l i b r a r y .o r g b y T i a n j i n U n i v e r s i t y o n 12/21/14. C o p y r i g h t A S C E . F o r p e r s o n a l u s e o n l y ; a l l r i g h t s r e s e r v e d .

Fig.14.Dynamic response considered at the peak load time of pavement system having strong thin base and clayey subgrade:?a ?horizontal microstrain predicted along the bottom of the AC layer ?Edge ?3-4?in Fig.9?and ?b ?vertical surface de?ection predicted along Edge ?1-2??de?ned in Fig.9

Fig.15.Dynamic response considered at the peak load time of pavement system having weak thin base and silty sand subgrade:?a ?horizontal D o w n l o a d e d f r o m a s c e l i b r a r y .o r g b y T i a n j i n U n i v e r s i t y o n 12/21/14. C o p y r i g h t A S C E . F o r p e r s o n a l u s e o n l y ; a l l r i g h t s r e s e r v e d .

is underlain by clayey soil;such decrease could reach to 15–20%,refer to Dondi ?1994?.Concerning fatigue strain,however,the static ?nite element analysis of Dondi ?1994?,which adopts the same pavement layers constitutive laws and almost similar height of the thick base considered in this paper,shows that a remarkable fatigue strain reduction ?reaching to 20%?results after placing the membrane at the bottom of the strong base underlain by clayey subgrade.Whereas the corresponding fatigue strain reduction obtained in the current study is relatively small ?does not exceed 4%?.Further investigations are required to arrest the cause of such discrepancy which could be due to the different system parameters or model features adopted for those somehow comp-arable investigations.The writers have found it dif?cult to locate other numerical studies that analyzed analogous pavement structures and covered the parameters examined in this paper.Hence complete comparison of all observations obtained from the current study with those deduced from previous ?nite element investigations of geosynthetic-reinforced conventional ?exible pavement systems was not feasible.

Conclusion

A series of ?nite element simulations are carried out to evaluate the bene?ts of integrating a high modulus geosynthetic into the pavement foundation.The simulations are conducted under a parametric study to investigate the bene?cial effects of geosyn-thetic reinforcement to the fatigue and rutting strain criteria,and how such effects are in?uenced by the base quality and thickness as well as the subgrade quality.The following conclusions can be drawn form the model parametric study.

1.When the geosynthetic reinforcement is placed at the

bottom of the AC layer,it leads to the highest reduction of the fatigue strain criterion ??t max ?.Such reduction,which reaches 48%,is practically independent of the base thickness and foundation quality.

2.Placing geosynthetic at the lower third of base leads to a

tangible decrease in ?t max ;this decrease is more pronounced when using a stronger base.Moreover,when reinforcing a weak base,the decrease in ?t

max obtained after geosynthetic reinforcement is used becomes more pronounced in the case of founding on clayey subgrade.

3.The geosynthetic reinforcement potential for decreasing the

rutting strain ??c max ?and surface de?ection is much more pronounced when using it in the thin base pavement of only 152.4mm ?6in.?.The reduction of resulting strain ?c

max for the reinforced systems ?c max

ranges between 2and 34%.4.Of the three locations examined for the geosynthetic rein-forcement,the best location which results in the highest reduction in the value of rutting strain ?c

max and surface de?ection,regardless of the subgrade quality,is at 1/3of the base thickness from the bottom.

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E .

F o r p e r s o n a l u s e o n l y ; a l l r i g h t s r e s e r v e d .

3D打印技术学习心得

“3D打印与激光再制造技术”学习心得张向军一、对3D打印技术的基本认知 3D打印就是将计算机中设计的三维模型分层，得到许多二维平面图形，再利用各种材质的粉末或熔融的塑料或其它材料逐层打印这些二维图形，堆叠成为三维实体。作为3D打印技术包括了三维模型的建模、机械及其自动控制（机电一体化）、模型分层并转化为打印指令代码软件等技术。不远的将来，我们完全可以用电脑把自己想要的东西设计出来，然后进行三维打印，就像我们现在可以在线编辑文档一样。通过电子设计文件或设计蓝图，3D打印技术将会把数字信息转化为实体物品。当然，这还不是3D打印的全部，3D打印最具魔力的地方是，它将给材料科学、生物科学带来翻天覆地的变化，最终的结果是科学技术和创新呈现爆发式的变革。 3D打印最直接的效益，就是对材料行业的拉动，随着3D产业规模的扩大，必将推动材料行业的不断变革。 3D打印机本是一种相对粗陋的机器，从工厂诞生，然后走进了家庭、企业、学校、厨房、医院、甚至时尚T台。但是一旦将3D打印机与当今发达的数字技术相结合，奇迹就发生了。再加上互联网的普及以及微小而成本低廉的电子电路的广泛使用，在材料科学和生物技术取得日新月异进步的今天，3D打印应用前景简直令人不可想象！二、3D打印的应用前景有了3D激光扫描仪，我们可以从市场上采购造型优美的后配重成品，采用逆向工程技术进行3D扫描后,适当修型再转化为3D图纸为我所用。修改后配重也可用3D打印机做出样品，这种3D模型外观上、结构上与设计实体完全一致，

非常直观。三、3D打印技术应用的局限性 3D打印结合了智能制造技术、自动控制技术和新材料技术，确实具备了引领第三次工业革命的有利条件，但是3D打印技术的大规模工业化应用还存在诸多限制。首先3D打印的材料品种单一，价格也过于昂贵，用于打印样品则可，用于批量生产则经济上决不可行。其次从效率上来说，采用3D打印技术工艺生产一个零件还是过于浪费时间了。其三，3D打印零部件的内在质量可靠性仍然存疑。采用金属粉末加上激光烧结和激光熔覆技术打印的零部件，其内在金属结构与采用现代冶金技术生产的零部件，在组织的致密性、结合的紧密性方面差距很大，影响3D打印零部件的结构强度。因此3D打印技术现阶段真正的实际应用，仅仅在产品研发过程的样品制造、工业生产中的砂型制造、生物医学上的器官仿生等方面较为成熟。那些3D技术打印的裙子、鞋子不过是艺术家自娱自乐的哗众取宠罢了。至于劳心费力的捣鼓出一个3D打印的水果，除了追求标新立异之外没有任何现实意义！四、对我国发展3D产业技术的几点思考 3D技术产业化发展有其局限性，存在诸多急需突破的技术瓶颈，能否真正引领第三次工业革命浪潮尚无定论。但3D 打印毕竟是代表制造技术发展方向的前沿技术，从国家层面还是要提前谋划、提前布局、紧密跟踪。首先，要从小学阶段开始在学校普及3D打印知识教育，让孩子们从小接触3D打印技术，有利于培养他们的动手能力和创新精神。桌面级3D打印机价格已经非常便宜，完全具备全面推广条件。其次，着力培养大型3D打印和扫描技术企业，组建3D产业技术国家队，壮大企业实力，参与国际竞争。目前我国3D制造企业规模偏小，实力不强，大多数在破产的边缘苦苦挣扎，很难与国外的大公司展开真正意义上的

3d打印实习感悟心得

D 打印实践报告班级：工设一班学号：311317040124 姓名：胡明亮

3d打印结课总结我在网络上查阅到3D打印是快速成型技术的一种，它是一种以数字模型文件为基础，运用粉末状金属或塑料等可粘合材料，通过逐层打印的方式来构造物体的技术。3D打印通常是采用数字技术材料打印机来实现的。常在模具制造、工业设计等领域被用于制造模型，后逐渐用于一些产品的直接制造，已经有使用这种技术打印而成的零部件。该技术在珠宝、鞋类、工业设计、建筑、工程和施工（AEC）、汽车，航空航天、牙科和医疗产业、教育、地理信息系统、土木工程、枪支以及其他领域都有所应用。3D打印存在着许多不同的技术。它们的不同之处在于以可用的材料的方式，并以不同层构建创建部件。3D打印常用材料有尼龙玻纤、耐用性尼龙材料、石膏材料、铝材料、钛合金、不锈钢、镀银、镀金、橡胶类材料。 3d打印技术的出现给工业设计的发展带来了新的契机，以往我们使用手绘、计算机渲染等方式来表达设计造型，这些方式虽然直观但并没有实体模型来的生动。同时3d打印的出现使得原始的设计流程变得精简，使设计师能够专注于产品形态创意和功能创新，即设计即生产。产品的造型设计向着多样化方向发展，由于3d打印的出现某些产品的制造出现了转机。通俗地说，3D打印机是可以“打印”出真实的3D物体的一种设备，比如打印一个机器人、打印玩具车，打印各种模型，甚至是食物等等。之所以通俗地称其为“打印机”是参照了普通打印机的技术原理，因为分层加工的过程与喷墨打印十分相似。这项打印技术称

为3D立体打印技术。在实习中我了解到了打印的基本原理和步骤，首先在电脑中安装打印机驱动程序，然后导入模型图调试机器，开始打印，打印过程中打印机将材料加热融化形成流体，最后流体经过导入的程序控制在底盘上一层一层的形成模型。也就是说日常生活中使用的普通打印机可以打印电脑设计的平面物品，而所谓的3D打印机与普通打印机工作原理基本相同，只是打印材料有些不同，普通打印机的打印材料是墨水和纸张，而3D打印机内装有金属、陶瓷、塑料、砂等不同的“打印材料”，是实实在在的原材料，打印机与电脑连接后，通过电脑控制可以把“打印材料”一层层叠加起来，最终把计算机上的蓝图变成实物。我们使用的都是桌面级的打印机，打印出模型的分辨率和大小都有很大的限制。我在新闻上了解到几年前就有打印出的金属手枪，无人飞机等问世了，前年我国也有“土豪金”汽车问世，这些都说明3d打印的前景十分广阔，将来能够应用到医疗、军事、建筑、航天等各个领域。但就目前来看3d打印的发展还有很长一段路要走，首先材料就是一个大问题，3D打印的产品只能看不能用，因为这些产品上不能加上电子元器件，无法为电子产品量产。3D打印即使不生产电子产品，但受材料的限制，可以生产的其他产品也很少，即使生产出来的产品，也无法量产，而且一摔就碎。在这方面我也一些体会，因为我们所使用的打印机材料就受到一定限制。同时，3d打印如果真的发展下去也会收到各个方面的制约，比如日本的一个青年就因为打印枪支而被起诉，更重要的是知识产权将会收到更大的冲击，如今的中国山寨抄袭横行，更何况3d打印普及以后呢。在3d打印实习中也出现了一些问题，比如打印前的设置参数有问题导致模型在打印过程中坍塌，结束时取下底座不小心导致模型损坏等…但总的来说我还是收获了很多，熟悉了基本的打印机操作步骤，了解了打印原理和注意事项，这为我以后打印自己的设计积累了丰富的经验。

3D打印技术学习心得

“3D打印与激光再制造技术”学习心得一、对3D打印技术的基本认知 3D打印就是将计算机中设计的三维模型分层，得到许多二维平面图形，再利用各种材质的粉末或熔融的塑料或其它材料逐层打印这些二维图形，堆叠成为三维实体。作为3D打印技术包括了三维模型的建模、机械及其自动控制（机电一体化）、模型分层并转化为打印指令代码软件等技术。不远的将来，我们完全可以用电脑把自己想要的东西设计出来，然后进行三维打印，就像我们现在可以在线编辑文档一样。通过电子设计文件或设计蓝图，3D打印技术将会把数字信息转化为实体物品。当然，这还不是3D打印的全部，3D打印最具魔力的地方是，它将给材料科学、生物科学带来翻天覆地的变化，最终的结果是科学技术和创新呈现爆发式的变革。 3D打印最直接的效益，就是对材料行业的拉动，随着3D产业规模的扩大，必将推动材料行业的不断变革。 3D打印机本是一种相对粗陋的机器，从工厂诞生，然后走进了家庭、企业、学校、厨房、医院、甚至时尚T台。但是一旦将3D打印机与当今发达的数字技术相结合，奇迹就发生了。再加上互联网的普及以及微小而成本低廉的电子电路的广泛使用，在材料科学和生物技术取得日新月异进步的今天，3D打印应用前景简直令人不可想象！二、3D打印在我公司的应用前景我们*****公司是一家叉车制造企业，每年都会进行不间断的新产

品研发。在这个过程中，3D扫描和3D打印技术有着良好的应用前景。譬如叉车的后配重由众多复杂曲面连接而成，设计上极为困难。有了3D激光扫描仪，我们可以从市场上采购造型优美的后配重成品，采用逆向工程技术进行3D扫描后,适当修型再转化为3D图纸为我所用。修改后配重也可用3D打印机做出样品，供领导决策时使用。这种3D模型外观上、结构上与设计实体完全一致，非常直观，有助于公司领导快速决策。因此3D打印技术的成功应用，必将加快我公司产品研发进度，缩短产品研发周期，提高市场响应能力！三、3D打印技术应用的局限性 3D打印结合了智能制造技术、自动控制技术和新材料技术，确实具备了引领第三次工业革命的有利条件，但是3D打印技术的大规模工业化应用还存在诸多限制。首先3D打印的材料品种单一，价格也过于昂贵，用于打印样品则可，用于批量生产则经济上决不可行；其次从效率上来说，采用3D打印技术工艺生产一个零件还是过于浪费时间了；其三，3D打印零部件的内在质量可靠性仍然存疑。采用金属粉末加上激光烧结和激光熔覆技术打印的零部件，其内在金属结构与采用现代冶金技术生产的零部件，在组织的致密性、结合的紧密性方面差距很大，影响3D打印零部件的结构强度。因此3D打印技术现阶段真正的实际应用，仅仅在产品研发过程的样品制造、工业生产中的砂型制造、生物医学上的器官仿生等方面较为成熟。那些3D 技术打印的裙子、鞋子不过是艺术家自娱自乐的哗众取宠罢了。至于劳心费力的捣鼓出一个3D打印的水果，除了追求标新立异之外没有

3D打印技术学习心得

3D打印与激光再制造技术”学习心得向军一、对3D打印技术的基本认知 D打印就是将计算机中设计的三维模型分层，得到许多二维平面图形，再利用各种材质的粉末或熔融的塑料或其它材料逐层打印这些二维图形，堆叠成为三维实体。作为3D打印技术包括了三维模型的建模、机械及其自动控制（机电一体化）、模型分层并转化为打印指令代码软件等技术。远的将来，我们完全可以用电脑把自己想要的东西设计出来，然后进行三维打印，就像我们现在可以在线编辑文档一样。通过电子设计文件或设计蓝图，3D打印技术将会把数字信息转化为实体物品。当然，这还不是3D打印的全部，3D打印最具魔力的地方是，它将给材料科学、生物科学带来翻天覆地的变化，最终的结果是科学技术和创新呈现爆发式的变革。 D打印最直接的效益，就是对材料行业的拉动，随着3D产业规模的扩大，必将推动材料行业的不断变革。

D打印机本是一种相对粗陋的机器，从工厂诞生，然后走进了家庭、企业、学校、厨房、医院、甚至时尚T台。但是一旦将3D打印机与当今发达的数字技术相结合，奇迹就发生了。再加上互联网的普及以及微小而成本低廉的电子电路的广泛使用，在材料科学和生物技术取得日新月异进步的今天，3D打印应用前景简直令人不可想象！二、3D打印的应用前景了3D激光扫描仪，我们可以从市场上采购造型优美的后配重成品，采用逆向工程技术进行3D扫描后,适当修型再转化为3D图纸为我所用。修改后配重也可用3D打印机做出样品，这种3D模型外观上、结构上与设计实体完全一致，非常直观。三、3D打印技术应用的局限性 D打印结合了智能制造技术、自动控制技术和新材料技术，确实具备了引领第三次工业革命的有利条件，但是3D打印技术的大规模工业化应用还存在诸多限制。首先3D打印的材料品种单一，价格也过于昂贵，用于打印样品则可，用于批量生产则经济上决不可行；其次从效率上来说，采用3D打印技术工艺生产一个零件还是过于浪费时间了；其三，3D打印零部件的内在质量可靠性仍然存疑。采用金属粉末加上激光烧结和激光熔覆技术打印的零部件，其内在金属结构与采用现代冶金技术生产的零部件，在组织的致密性、结合的紧密性方面差距很大，影响3D打印零部件的结构强度。因此3D打印技术现阶

3D打印技术学习心得

3D打印技术学习心得文件排版存档编号：[UYTR-OUPT28-KBNTL98-UYNN208]

3D打印机做出样品，这种3D模型外观上、结构上与设计实体完全一致，非常直观。三、3D打印技术应用的局限性 3D打印结合了智能制造技术、自动控制技术和新材料技术，确实具备了引领第三次工业革命的有利条件，但是3D打印技术的大规模工业化应用还存在诸多限制。首先3D打印的材料品种单一，价格也过于昂贵，用于打印样品则可，用于批量生产则经济上决不可行；其次从效率上来说，采用3D打印技术工艺生产一个零件还是过于浪费时间了；其三，3D打印零部件的内在质量可靠性仍然存疑。采用金属粉末加上激光烧结和激光熔覆技术打印的零部件，其内在金属结构与采用现代冶金技术生产的零部件，在组织的致密性、结合的紧密性方面差距很大，影响3D打印零部件的结构强度。因此3D打印技术现阶段真正的实际应用，仅仅在产品研发过程的样品制造、工业生产中的砂型制造、生物医学上的器官仿生等方面较为成熟。那些3D技术打印的裙子、鞋子不过是艺术家自娱自乐的哗众取宠罢了。至于劳心费力的捣鼓出一个3D打印的水果，除了追求标新立异之外没有任何现实意义！四、对我国发展3D产业技术的几点思考 3D技术产业化发展有其局限性，存在诸多急需突破的技术瓶颈，能否真正引领第三次工业革命浪潮尚无定论。但3D 打印毕竟是代表制造技术发展方向的前沿技术，从国家层面还是要提前谋划、提前布局、紧密跟踪。首先，要从小学阶段开始在学校普及3D打印知识教育，让孩子们从小接触3D打印技术，有利于培养他们的动手能力和创新精神。桌面级3D打印机价格已经非常便宜，完全具备全面推广条件。其次，着力培养大型3D打印和扫描技术企业，组建3D产业技术国家队，壮大企业实力，参与国际竞争。目前我国3D制造企业规模偏小，实力不强，大多数在破产的边缘苦苦挣扎，很难与国外的大公司展开真正意义上的竞争，因此政府主导的

3D打印技术学习心得体会总结范文

3D打印技术学习心得体会总结范文 3D打印技术又称三维打印技术，是一种以数字模型文件为基础，通过逐层打印的方式来构造物体的技术。下面就让X给大家分享几篇3D打印技术学习心得体会吧，希望能对你有帮助! 3D打印技术学习心得体会篇一 3D打印是一种通过材料逐层添加制造三维物体的变革性、数字化增材制造技术，它将信息、材料、生物、控制等技术融合渗透，将对未来制造业生产模式与人类生活方式产生重要影响。3D打印这种智能制造的逻辑轨迹是控制物质的形状、控制物质的构成和控制行为，也就是实现物体在结构、材料和活性上的有机统一。越来越多的迹象表明，3D打印技术已经从实验室和工厂逐渐走出来了，并且走进学校和家庭，与我们每个普通人的生活息息相关。这样会极大地冲击我们的工作方式，或者增强很多行业的生命力。然而我们必须清

醒地意识到3D打印技术也会催生大量前所未有的行业和巨大机遇，我们必须牢牢的抓住机遇，因为第三次工业革命的序幕已经拉开。目前3D印刷技术已深入到了各行各业，给人以耳目一新之感。 3D印刷术被看作是信息时代印刷术的一次惊人的飞跃，有人将它与开启工业革命的蒸汽机相提并论。3D打印机能做:艺术品、精密零件制造业、家庭装饰、建筑、食品和服装、人偶玩具、珠宝、医学、产品原型等。关于3D打印技术的几点思考，在信息技术飞速发展的今天，我校的教学也应该与时俱进，例如在我们动漫专业的设计当中引入3D打印技术，电子创新班的产品设计中引入3D打印技术，在通信维修综合布线中引入3D印刷技术，机器人设计中引入3D打印技术等等，将对我们的学生更加有学习的成就感。3D打印技术学习心得体会篇二通过为期两周的3D打印技术的培训与学习，对3D打印技术有了更深刻的认识和理解。现将两周(12月4号-13号)的学习心

3D打印技术学习心得

与D打E卩与激光再制造技术〃学习心得张向军一、对3D打印技术的基本认知 3D打印就是将计算机中设计的三维模型分层，得到许多二维平面图形，再利用各种材质的粉末或熔融的塑料或其它材料逐层打印这些二维图形，堆叠成为三维实体。作为3D打印技术包括了三维模型的建模、机械及其自动控制（机电一体化）、模型分层并转化为打印指令代码软件等技术。不远的将来，我们完全可以用电脑把自己想要的东西设计出来，然后进行三维打印，就像我们现在可以在线编辑文档一样。通过电子设计文件或设计蓝图，3D打印技术将会把数字信息转化为实体物品。当然，这还不是3D打印的全部，3D打印最具魔力的地方是，它将给材料科学、生物科学带来翻天覆地的变化，最终的结果是科学技术和创新呈现爆发式的变革。 3D打印最直接的效益，就是对材料行业的拉动，随着3D产业规模的扩大，必将推动材料行业的不断变革。 3D打印机本是一种相对粗陋的机器，从工厂诞生，然后走进了家庭、企业、学校、厨房、医院、甚至时尚T台。但是一旦将3D打印机与当今发达的数字技术相结合，奇迹就发生了。再加上互联网的普及以及微小而成本低廉的电子电路的广泛使用，在材料科学和生物技术取得日新月异进步的今天，3D打印应用前景简直令人不可想象！

二、3D打印的应用前景有了3D激光扫描仪，我们可以从市场上采购造型优美的后配重成品，采用逆向工程技术进行3D扫描后，适当修型再转化为3D图纸为我所用。修改后配重也可用3D打印机做出样品，这种3D模型外观上、结构上与设计实体完全一致，非常直观。三、3D打印技术应用的局限性 3D打印结合了智能制造技术、自动控制技术和新材料技术，确实具备了引领第三次工业革命的有利条件，但是3D打印技术的大规模工业化应用还存在诸多限制。首先3D打印的材料品种单一，价格也过于昂贵，用于打印样品则可，用于批量生产则经济上决不可行；其次从效率上来说，采用3D打印技术工艺生产一个零件还是过于浪费时间了；其三，3D打印零部件的内在质量可靠性仍然存疑。釆用金属粉末加上激光烧结和激光熔覆技术打印的零部件，其内在金属结构与采用现代冶金技术生产的零部件，在组织的致密性、结合的紧密性方面差距很大，影响3D 打印零部件的结构强度。因此3D打印技术现阶段真正的实际应用，仅仅在产品研发过程的样品制造、工业生产中的砂型制造、生物医学上的器官仿生等方面较为成熟。那些3D技术打印的裙子、鞋子不过是艺术家自娱自乐的哗众取宠罢了。至于劳心费力的捣鼓出一个3D打印的水果，除了追求标新立异之外没有任何现实意义！四、对我国发展3D产业技术的几点思考 3D技术产业化发展有其局限性，存在诸多急需突破的技术瓶颈，能否真正引领第三次工业革命浪潮尚无定论。但3D打印毕竟是代表制造技术

3D打印机实训报告

快速成型与快速模具3D打印实训报告书姓名：吴登庆学号：1206240218 班级：12机械（2）班专业：机械设计与制造学院：机电工程与自动化学院学校：黎明职业大学指导老师：辛勤颖李丽环

一、3D打印机的介绍 1、3D打印机的介绍 3D打印（3D printing）也称为“增材制造（Additive Manufacturing）”，它是新兴的一种快速成型技术。与传统的减材制造工艺不同，3D打印是以数据设计文件为基础，将材料逐层沉积或黏合以构造成三维物体的技术。 3D打印的思想萌芽和实验探索由来已久，但现代意义上的3D打印技术于20世纪80年代中期诞生于美国。Charles Hull（3D Systems公司的创始人）和Scott Crump（Stratasys公司的创始人）是3D打印技术的先驱人物。1986年，Charles Hull发明了第一台3D打印机，之后成立了第一家3D打印公司3D Systems。1988年，3D Systems公司推出了世界上第一台基于SLA技术的商用3D打印机SLA-250，它的面世标志着3D打印商业化的起步。Scott Crump研发了另一3D打印主流技术FDM，于1989年申请了美国专利并创立了Stratasys 公司，1992年推出第一台基于FDM技术的“3D Modeler”打印机。经过二十余年的发展，3D打印机在工业领域已经有一定的应用基础。随着计算能力、设计软件、新材料及互联网进步的不断推动，3D打印技术近年来发展迅速，应用领域不断拓宽，显示出巨大的发展潜力。3D打印与传统制造业的最大区别在于产品成型的过程上。在传统的制造业，整个制造流程一般需要经过开模具、铸造或锻造、切割、部件组装等过程成型。3D打印则免去了复杂的过程，无需模具，一次成型。因此，3D打印可以克服一些传统制造上无法达成的设计，制作出更复杂的结构。随着技术的不断进步，3D打印在铸造精度上已经可以与传统方式相媲美，但是在大规模生产上，3D打印目前仍无法获得规模经济，在成本上和效率上不具优势。因此，3D打印主要被应用于个性化、小批量和高精度的产品制造上。 2.用途 3D打印技术可用于珠宝，鞋类，工业设计，建筑，工程和施工（AEC），汽车，航空航天，牙科和医疗产业，教育，地理信息系统，土木工程，和许多其他领域。常常在模具制造、工业设计等领域被用于制造模型或者用于一些产品的直接制造，意味着这项技术正在普及。通过3D打印机也可以打印出食物，是3D打印机未来的发展方向。

3D打印技术学习心得

3D打印技术学习心得一、对3D打印技术的基本认知 3D打印是一种通过材料逐层添加制造三维物体的变革性、数字化增材制造技术，它将信息、材料、生物、控制等技术融合渗透，将对未来制造业生产模式与人类生活方式产生重要影响。3D打印这种智能制造的逻辑轨迹是控制物质的形状、控制物质的构成和控制行为，也就是实现物体在结构、材料和活性上的有机统一。越来越多的迹象表明，3D打印技术已经从实验室和工厂逐渐走出来了，并且走进学校和家庭，与我们每个普通人的生活息息相关。这样会极大地冲击我们的工作方式，或者增强很多行业的生命力，也或者导致某些行业走向消亡。然而我们必须清醒地意识到3D打印技术也会催生大量前所未有的行业和巨大机遇，我们必须牢牢的抓住机遇，因为第三次工业革命的序幕已经拉开。二、3D打印机能做的10件事目前3D印刷技术已深入到了各行各业，给人以耳目一新之感。3D印刷术被看作是信息时代印刷术的一次惊人的飞跃，有人将它与开启工业革命的蒸汽机相提并论。以下是美国媒体评出的3D打印机能做的10件事情。 1.艺术品 3D印刷能够创作出许多令人惊叹的艺术作品。这些作品如果用常规方法创作，要么十分困难，要么费时费力，这里3D印刷就显现

了其优势。3D打印技术可以最大程度还原艺术品的真实性，而且确保了制作过程的稳定性。 2.精密零件制造业在诸多领域，3D印刷还只是一项不入主流的“花哨技术”，但在零件制造行业，这项技术正在完全取代传统制造技术。精确和一次成型对于很多精密零件来说，显然如生命般重要，3D打印技术恰好能天衣无缝地满足这些需求，这也使得它具备了传统工艺无法比拟的优势。 3.家庭装饰如今家庭装饰都讲求个性，追求感官愉悦，这就给了3D印刷技术发挥的空间。现已有多家公司提供利用3D印刷技术制作个性装饰的服务，可以根据客户的要求制作出他们满意的各种装饰物。相信有一天，你也会在这里找到专属于自己的装饰品。 4.建筑业意大利发明家恩里科·迪尼发明了一台巨大的3D打印机，可以用沙子直接打印立体的建筑。有了这台机器，未来不搭脚手架，不需要工人，人们就能造房子。印刷过程由一层薄薄的沙子开始，印刷机从喷嘴处喷出以镁为主要原料的粘合胶，这些粘合胶跟沙子结合并在印刷机对其施压后变成岩石。之后再放上一层薄薄的沙子，重复以上的操作，岩石层就会越来越厚，最终印刷成设计中所需要的构造物形状。成品可以是一座雕塑或整个大教堂。迪尼目前已经做成的实验品是一只布满空洞的蛋状

3D打印技术学习心得

3D打印技术学习心得标准化工作室编码[XX968T-XX89628-XJ668-XT689N]

生物技术取得日新月异进步的今天，3D打印应用前景简直令人不可想象！二、3D打印的应用前景有了3D激光扫描仪，我们可以从市场上采购造型优美的后配重成品，采用逆向工程技术进行3D扫描后,适当修型再转化为3D图纸为我所用。修改后配重也可用3D打印机做出样品，这种3D模型外观上、结构上与设计实体完全一致，非常直观。三、3D打印技术应用的局限性 3D打印结合了智能制造技术、自动控制技术和新材料技术，确实具备了引领第三次工业革命的有利条件，但是3D打印技术的大规模工业化应用还存在诸多限制。首先3D打印的材料品种单一，价格也过于昂贵，用于打印样品则可，用于批量生产则经济上决不可行；其次从效率上来说，采用3D打印技术工艺生产一个零件还是过于浪费时间了；其三，3D打印零部件的内在质量可靠性仍然存疑。采用金属粉末加上激光烧结和激光熔覆技术打印的零部件，其内在金属结构与采用现代冶金技术生产的零部件，在组织的致密性、结合的紧密性方面差距很大，影响3D打印零部件的结构强度。因此 3D打印技术现阶段真正的实际应用，仅仅在产品研发过程的样品制造、工业生产中的砂型制造、生物医学上的器官仿生等方面较为成熟。那些3D技术打印的裙子、鞋子不过是艺术家自娱自乐的哗众取宠罢了。至于劳心费力的捣鼓出一个3D打印的水果，除了追求标新立异之外没有任何现实意义！

3d打印实习感悟心得

3Ｄ打印实践报告班级:工设一班学号:3１１３1704０124 姓名:胡明亮 3ｄ打印结课总结我在网络上查阅到3Ｄ打印就是快速成型技术得一种,它就是一种以数字模型文件为基础,运用粉末状金属或塑料等可粘合材料,通过逐层打印得方式来构造物体得技术。3D打印通常就是采用数字技术材料打印机来实现得。常在模具制造、工业设计等领域被用于制造模

型,后逐渐用于一些产品得直接制造,已经有使用这种技术打印而成得零部件。该技术在珠宝、鞋类、工业设计、建筑、工程与施工(AEC)、汽车,航空航天、牙科与医疗产业、教育、地理信息系统、土木工程、枪支以及其她领域都有所应用。3D打印存在着许多不同得技术。它们得不同之处在于以可用得材料得方式,并以不同层构建创建部件。3D打印常用材料有尼龙玻纤、耐用性尼龙材料、石膏材料、铝材料、钛合金、不锈钢、镀银、镀金、橡胶类材料。 3d打印技术得出现给工业设计得发展带来了新得契机,以往我们使用手绘、计算机渲染等方式来表达设计造型,这些方式虽然直观但并没有实体模型来得生动。同时3d打印得出现使得原始得设计流程变得精简,使设计师能够专注于产品形态创意与功能创新,即设计即生产。产品得造型设计向着多样化方向发展,由于3d打印得出现某些产品得制造出现了转机。通俗地说,3Ｄ打印机就是可以“打印”出真实得3Ｄ物体得一种设备,比如打印一个机器人、打印玩具车,打印各种模型,甚至就是食物等等。之所以通俗地称其为“打印机"就是参照了普通打印机得技术原理,因为分层加工得过程与喷墨打印十分相似。这项打印技术称为３D立体打印技术。在实习中我了解到了打印得基本原理与步骤,首先在电脑中安装打印机驱动程序,然后导入模型图调试机器,开始打印,打印过程中打印机将材料加热融化形成流体,最后流体经过导入得程序控制在底盘上一层一层得形成模型。也就就是说日常生活中使用得普通打印机可以打印电脑设计得平面物品,而所谓得3D打印机与普通打印机工作原理基本相同,只就是打印材料有些不同,普通打印机得打印材料就是墨水与纸张,而3D打印机内装有金属、陶瓷、塑料、砂等不同得“打印材料”,就是实实在在得原材料,打印机与电脑连接后,通过电脑控制可以把“打印材料”一层层叠加起来,最终把计算机上得蓝图变成实物。我们使用得都就是桌面级得打印机,打印出模型得分辨率与大小都有很大得限制。我在

3D打印技术学习心得

3D打印技术学习心得 This model paper was revised by the Standardization Office on December 10, 2020

3d打印DIY全解

既不是传统意义上的机械工程师，也不是电子工程师，机电控制是个吸引我又颇有难度的事情。然而3D打印技术却能让每个人都可以去尝试、去制作、去分享。面对这个号称是“第三次工业革命”，有可能改变整个制造加工业概念的新技术，我充满了好奇和去了解它的渴望。非常幸运的是，我正生活在这个最容易接触到前沿科技的国家，我也拥有足够的知识背景和经济基础，去真正实现一次自己的爱好。 2004年起加速发展的个人3D打印机行业，出现了大量优秀的创业者和投资者。这些新企业加上科研院校里精英们的努力，让该技术日渐成熟，成本逐渐降低。个人3D打印机从几年前的几万美元开始，下降到现在普遍在几千美元甚至低至400美元的价位，好像已经有可能真正涉足家庭环境了。想象1975年左右个人PC的开始普及，这难道不是一件让人兴奋的现象嘛？也许一个新的时代已经到来，而且就在我们身边！开源的https://www.wendangku.net/doc/1115626353.html,社区，引领我相对轻松的进入这个领域。但我还称不上是一个宣扬者和推广者，最多是一个积极的学生和入门者。我还没攒够足够的知识和经验，来推动它的进步和改善。但相信我也可以尽自己的一份力量，引发更多的人（特别是国人）对3D 打印的兴趣。因此我将在此个人博客上记录一切有关制造我的个人3D打印机的内容，分享经验，重要的是作为一个信息收集和归纳的地方。当然如果能遇到有相同爱好的是再好不过了。

我选择了RepRap开源设计里最成熟的机型Prusa Mendel（上图左），这是RepRap 推荐初学者入门的两个机型之一，另一个是更加紧凑小巧一点的Huxley（上图右）。它俩从结构上来说很类似，但我之前一直在犹豫要不要节省点空间，Prusa大概45cm见方，Huxley 是28cm（很适合我那不算大的电脑桌）。但是最终让我敲定Prusa的有这么几个原因： ?Prusa更加成熟，现在已经发展到第二代，网上有很多文档和资料，各种机友经验总结，资源相对比较容易找——无论是想买别人已经安装好的机型，还是购买组装套餐自己装配，还是从0开始一件件零部件搜集的完全式DIY——都是可行的方案。而Huxley目前还只能是从RepRap创始者英国Bath大学的Adrian Bowler的公司（RepRapPro Ltd.)里买组装套餐。我个人比较喜欢DIY，制造机器的过程比得到一部机器本身更加重要，Huxley少了这些乐趣。 ?打印尺寸上Prusa可以做到常规的8英寸见方，换成公制是20公分左右。Huxley 就小了点，只有14公分。虽然目前我还不清楚我将来会打印多大的东西，但……bigger is better，老美就喜欢越大的越好。 ?价格上Huxley不占优势，主要原因还是没法DIY。以上三种制作方案成本是逐渐降低的，一套Huxley组装套餐在RepRapPro公司主页上要卖669美刀（含运费）。而Prusa 采用完全DIY的方式的话，基本可以控制在600美刀之内（当然也要看采购产品的质量及性能要求）。这样一来Huxley就只有占地面积小这一个优势了。这两天已经开始在网上各处采购零部件了，对一个新手来说算是件挺复杂也有意思的事情。后面会将选购各部件的心得体会及费用明细也记录下来。虽然我也喜欢尽量便宜的

3d打印培训心得体会

3D打印培训心得体会石洪周 2015.12.3

2015年9月5日-8日，本人有幸几位同事一起参加了云南省省教厅、云南昆明理工恒达科技有限公司开展的3D打印培训班。在此次培训中，真的是让我大开眼界。平时，总认为3D打印技术是一种及其抽象的概念，而且它还是一种尖端的科技，一时半会儿不可能走进现实生活。“3D科技离我们的生活其实并不遥远，目前在建筑、医疗、军事、餐饮等行业都已实际运用。3D打印技术的发展将改变现有的学习模式、艺术想象甚至改变未来的生活方式。”这是此次培训负责人林功伟先生首先在开班典礼上给我们介绍3D打印，“3D科技离我们的生活其实并不遥远，”这就是我们初步了解的3D打印，概念已经不在那么抽象与模糊。接下来就是满满的理论与实践操作相结合的课程。通常理论课程会很无聊，因为有过很多类似的培训，说实在的真的很无聊。但这次的培训，我只能用“受益匪浅”这个词来形容。培训中，有专门讲授理论的主讲老师，还有专门教你操作的助教老师，一步一步让我们掌握相关理论与技术。通过这次的培训学习，我们了解到3D打印技术早在19世纪就以被应用，历经几个世纪不断发展他已经逐渐成为一种新型的工业制造工艺，而且还在蓬勃发展。基本掌握了3D扫描技术、3D修模技术和3D打印技术。不要以为3D打印很抽象，也不要认为3D打印很难，其实这个技术在将来的生活中将不在是神奇的东西，它将会走进人们的实际生活，与人们的生活息息相关，为人类的生活服务。

最关键的是在培训结束时，给我们大家来了一个大大的惊喜：我们全省参加培训的6000所学校将在年底前配备3D打印机，让我们将3D打印运用到教学中，这在培养学生的创意思维和创新实践能力方面将会有意想不到的功效，实在是太难得了。

3D打印实习感悟心得

3D打印实习感悟心得 Document serial number【LGGKGB-LGG98YT-LGGT8CB-LGUT-

3D 打印实践报告班级：工设一班姓名：胡明亮 3d打印结课总结我在网络上查阅到3D打印是快速成型技术的一种，它是一种以数字模型文件为基础，运用粉末状金属或塑料等可粘合材料，通过逐层打印的方式来构造物体的技术。3D打印通常是采用数字技术材料打印机来实现的。常在模具制造、工业设计等领域被用于制造模型，后逐渐用于一些产品的直接制造，已经有使用这种技术打印而成的零部件。该技术在珠宝、鞋类、工业设计、建筑、工程和施工（AEC）、汽车，航空航天、牙科和医疗产业、教育、地理信息系统、土木工程、枪支以及其他领域都有所应用。3D打印存在着许多不同的技术。它们的不同之处在于以可用的材料的方式，并以不同

层构建创建部件。3D打印常用材料有尼龙玻纤、耐用性尼龙材料、石膏材料、铝材料、钛合金、不锈钢、镀银、镀金、橡胶类材料。 3d打印技术的出现给工业设计的发展带来了新的契机，以往我们使用手绘、计算机渲染等方式来表达设计造型，这些方式虽然直观但并没有实体模型来的生动。同时3d打印的出现使得原始的设计流程变得精简，使设计师能够专注于产品形态创意和功能创新，即设计即生产。产品的造型设计向着多样化方向发展，由于3d打印的出现某些产品的制造出现了转机。通俗地说，3D打印机是可以“打印”出真实的3D物体的一种设备，比如打印一个机器人、打印玩具车，打印各种模型，甚至是食物等等。之所以通俗地称其为“打印机”是参照了普通打印机的技术原理，因为分层加工的过程与喷墨打印十分相似。这项打印技术称为3D立体打印技术。在实习中我了解到了打印的基本原理和步骤，首先在电脑中安装打印机驱动程序，然后导入模型图调试机器，开始打印，打印过程中打印机将材料加热融化形成流体，最后流体经过导入的程序控制在底盘上一层一层的形成模型。也就是说日常生活中使用的普通打印机可以打印电脑设计的平面物品，而所谓的3D打印机与普通打印机工作原理基本相同，只是打印材料有些不同，普通打印机的打印材料是墨水和纸张，而3D打印机内装有金属、陶瓷、塑料、砂等不同的“打印材料”，是实实在在的原材料，打印机与电脑连接后，通过电脑控制可以把“打印材料”一层层叠加起来，最终把计算机上的蓝图变成实物。我们使用的都是桌面级的打印机，打印出模型的分辨率和大小都有很大的限制。我在新闻上了解到几年前就有打印出的金属手枪，无人飞机等问世了，前年我国也有“土豪金”汽车问世，这些都说明3d打印的前景十分广阔，将来能够应用到医疗、军事、建筑、航天等各个领域。但就目前来看3d打印的发展还有很长一段路要走，首先材料

3D打印实训概况

3D打印实训区 1、概况：3D打印实训区位于工程训练中心厂房内，使用面积为：240平方米。其中模型设计教学和实训有24个工位。3D打印技术教学和实训有30个工位。 2、主要设备： ①多媒体教学系统2套 ②电脑26台 ③3D打印机27台套 3、实训项目和主要功能有：3D打印模型设计、打印机控制软件教学实训、各类3D打印机的工作原理、实操、维修等教学和实训。使学生全面掌握3D打印技术全过程，能独立完成产品设计和打印成品。 4、对应专业：机电一体化、3D打印技术、机械、数控、模具等专业规章制度：3D实验室制度建设 3D打印技术实验室是学院领导精心筹划创立的，为了营造创新的环境氛围，激发学生的创新潜能，提高学生学习上的上进心，促进3D打印技术的长远发展，特制订以下制度，望本专业学生上课时严格遵守。第一条行为规范 1、仪表：实训班级人员应仪表整洁、大方，夏天严禁穿拖鞋、超短裤进入教室以及实验室； 2、用语：实验室内应讲普通话，规范用语，不准讲脏话等不文明用语；

3、动作：班级同学上课举止典雅，不得有违反校规校纪的不文明行为；第二条学生管理制度： 1、严禁实验室内吸烟； 2、严禁实验室内喧哗、打闹、闲聊； 4、严禁上建模课时修改电脑桌面等相关程序设置； 5、严禁私自在电脑上安装游戏、下载观看电影、做与学习无关的事情。 6、实验室内的书刊、杂志及相关作品未经允许严禁带出实验室； 7、严禁故意损坏打印机设备及相关器材； 9、严禁带饭进入实验室。第三条实验室管理制度： 1、爱护公共财物，维护实验室财产安全； 2、离开实验室时检查机器是否关闭、断电。 3、做到随手关灯，人走灯灭； 4、实验室电脑及相关设备有专人维护，有问题及时上报； 8、使用结束后务必及时关闭各类用电设备，断开总电源，关闭门窗。第四条卫生管理： 1、每位班级人员有维护卫生的权利和义务； 2、应在进入和离开实验室时应做好个人卫生区的卫生清洁，保持物品摆放整洁；

3D打印策划书

篇一：3d打印产品市场营销方案南京***3d打印产品市场营销方案一、前言（一）公司简介南京***有限公司发展始于***年，公司主要业务方向为大数据和3d打印技术。（二）3d打印简介 3d打印原是快速成型技术中的一种工艺(3dp)，通过喷墨的方法用液体黏结提前铺好的粉末，以“打印”横截面的方式逐层创建各部件。由于它采用“加法”形成物体，故又被称为“增材制造”。近年来媒体将这一形象称谓推广到所有快速成型工艺—其基本原理均是由“打印”无数横截面累积而成的叠层制造，区别在于实现横截面的方式不同，如液体黏结、激光“烧融”等。南京***电子科技有限公司的3d打印产品，主要依托南京邮电大学先进技术研究院的3d打印实验室，面向市场，为客户提供多系列、个性化的系列3d打印产品。目前，实验室拥有3d 打印设备1台，近期还将采购更为先进的设备。二、市场分析（一）市场现状 3d打印机的应用对象可以是任何行业，根据2012年统计据，全球3d打印的应用领域，主要分布在消费性产品(29%)、汽车(19%)、医疗(13%)、教育(10%)、太空(8%)及工业机械(7%)等领域，不同应用领域所使用的3d打印设备，可区分为生产制造用、专业领域用、工作室用三个等级，其中5000美元以下的机型，2010年的销售量仅为5900台，预估至2012年将大幅成长至3.5万台，两年内销售量成长将近六倍。目前，中国市场上的 3d 打印机主要有三大类，分别是桌面级、工业级和生物医学级。桌面级 3d 打印机是 3d 打印技术里面最简单、科技含量最低，而且是未来最有可能在大众中得到普及的 3d 打印机，主要是满足设计、创意类行业需求，国内价位大都在 1 万元人民币左右。而由于我国工业化起步较晚、工业基础比较薄弱，中国工业级 3d 打印机的稳定性、精密度、材料等领域与国外还是有一些差距的。不过，中国在大型金属结构件直接制造方面也有自己的优势，中国率先突破了在大型复杂金属结构件制造方面的障碍，走在世界的前列。罗军预测，中国的 3d 打印市场将在三年内从目前的约 10 亿元人民币增长到 100 亿元。3d 打印技术前景可期，已渐入寻常百姓家。国际品牌 cube3d 打印机近日在中国电商网站京东商城上成功开售，这是全球知名品牌 3d systems 最新推出的第二代3d 打印机，也是目前最贴近家庭、个人用户的消费级 3d 打印机。此外，我国已经有部分新潮的企业开始使用 3d 打印技术，制造出玩具、家电等实体产品。3d 打印技术进入制造业的应用正逐步展开，促进产品走向精细化生产。 3d打印技术被称为第三次工业革命，其快速制造产品的模式为工业设计的发展带来了前所未有的机遇。可降低约 50%的制造费用，缩短 70%的加工周期，并能将复杂制造实现设计制造一体化。如果可以发展成熟，将极大的改变社会制造产业，因此现在关于3d打印的研究非常多，各大研究机构与企业都看好这一朝阳产业，以期在这一竞争中走在前面，获得更多的话语权！（二）swot分析目前，3d打印技术在我国仍属于一个新兴领域，其产业发展，必然会遇到众多的机遇和挑战，下面是有关3d打印产业发展swot分析：面对新的全球化竞争条件，国内3d打印产业发展虽然面临着这样那样的问题，但从整体来看，3d打印产业发展所面临的机遇远大于挑战。因此，我们需要在抓住3d打印技术在国内各领域不断应用推广的新机遇，抓住政府宏观政策扶持所带来的利好，精确定位市场，牢牢把握