Purpose of this study was to predict deformation and dimensions of the parts produced by a stereolithography system which transforms designs into actual prototypes within hours.
Part-building process, Part removal process, and postcure process were the most important steps which had a significant effect on dimensional accuracy. Part distortion due to shrinkage of the photopolymer was taken into consideration as that due to thermal strain. Because building method in the part-building process played an important role of causing distortion, the model-b representing the building method appropriately was proposed. Distortion of the part caused by the building process was much smaller than that caused by part removal process because the internal residual stress developed during building prcess was released upon removal of the part from the platform. In order to consider curing mechanism in the postcuring process, it is assumed that the postcure occured from the exterior surface to the interior. For modelling heat sink was given properly on the outside for the thermal stress analysis and the curing velocity was controlled.
As the numerical results obtained by the model-b are consistent with the experimental distortion results, the model-b is more appropriate for the modelling of each process and it was shown that the part distortion was computed adequately by using finite element program developed in the study.
