A phenomenological finite element model of stereolithography processing

Chambers, Robert S.; Guess, T.R.; Hinnerichs, Terry D.

doi:10.2172/212696

Cited by 13 publications

(12 citation statements)

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“…Chartoff [3] and Guess [4] measured physical properties during the solidification of different kinds of resins exposed to laser beams. In 1995, a threedimensional finite element method (FEM) simulation code [5] was developed. In the model, the curl distortion is caused by cure shrinkage during photopolymerization and it is uniform within the individually cured strand.…”

Section: Introductionmentioning

confidence: 99%

Compensation of distortion in the bottom exposure of stereolithography process

Huang

Lan

2005

Int J Adv Manuf Technol

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The rapid prototyping (RP) process is the fastest and most feasible method for prototype construction. However, with the use of any material or build method the phenomenon of volume shrinkage is unavoidable. It is known that volume shrinkage and curl distortion are the major causes that lead to poor accuracy of the built prototype. Subsequently, in order to improve the precision of dimension and volume shrinkage, more expensive equipment is used on the market. Also, it is expensive and inefficient to obtain better process parameters through trail and error in the RP process. In order to improve the precision of dimension, reduce the processing cost and the frequency of trail and error, this study first induces the concept of computeraided engineering (CAE) into the processing of RP, which uses a dynamic finite element simulation code to simulate the photopolymerization process, so as to reduce the time for selecting the processing parameters and obtain the distortion data. Second, by means of reverse distortion compensation to obtain a new CAD model, then it is sent to a RP machine for the actual prototyping processes, so as to obtain a more accurate precision. Finally, in order to confirm this method and restriction in experimental equipment, the stereolithography process and simple laser scanning path are chosen as examples. The results of the simulation and experiment prove that the method proposed herein is effective. It not only can reduce the cost of equipment but also obtain a better precision of dimension on final-parts at the same time. Besides, it is believed that this research method can be promoted to other materials or build methods in RP fabrication.

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Section: Introductionmentioning

confidence: 99%

Compensation of distortion in the bottom exposure of stereolithography process

Huang

Lan

2005

Int J Adv Manuf Technol

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“…In 1995, two three-dimensional finite element method (FEM) simulation computer programs [4,6] were developed. Both of them were based on the same mathematical model.…”

Section: Introductionmentioning

confidence: 99%

Curl Distortion Analysis During Photopolymerisation of Stereolithography Using Dynamic Finite Element Method

Huang

Jiang

2003

The International Journal of Advanced Manufacturing Technology

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Stereolithography is one of the rapid prototyping processes which uses a photopolymer as the raw material to build prototypes. The photopolymer absorbs energy by selective laser exposure. The curing effect starts when the absorbing energy exceeds a critical value, and the process is called photopolymerisation. The photopolymerisation changes the phase from liquid to solid. The cured volume can expand and then shrink on cooling. The process parameters such as the scanning speed, scanning path, scanning pitch, and the slicing thickness, lead to different shrinkage and curl distortion, so, the photopolymerisation process is a dynamic material behaviour. In this study, a dynamic finite element simulation code has been developed to simulate the photopolymerisation process. The simulated result for a suspended beam which corresponds to the process parameters shows that a short raster causes less curl distortion than a long raster. The experimental result agrees very well with the simulated result.

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“…These tools include phenomenological material models of the solidifying resins and a 3D finite element model that incorporates time varying material behavior, laser path dependence, and structural linkage. Results of 1) the development of a 3D finite element code architecture to numerically simulate part-building in the stereolithography process, and 2) the investigation of the possibility of analyzing part-building using a simple phenomenological model of solidifjring resins are reported elsewhere [2,3]. This report describes the experimental portion of the LDRD program; both single strand and bulk material properties are reported.…”

Section: An Ldrd Program Entitled "Stereolithography Manufacturing Prmentioning

confidence: 99%

“…The curl measured in the solidified parts was compared to model predictions obtained by analyzing the two build styles in a 3D finite element code [3]. The finite element program contained three important build features: 1) time varying material behavior; 2) laser path react (solidifying and shrinking).…”

Section: Curl Measurementsmentioning

confidence: 99%