Abstract: According to the deformation mechanism of mechanical parts in the process of the stereolithography rapid prototyping(SL-RP) and the theory of temperature stress of thin plate with small deflection, the distortion deformation of the plate parts is studied in detail and the mechanical equivalent model of resin phase change shrinkage in SL rapid prototyping is presented. The time-varying stiffness of the slab and equivalent force of resin phase change shrinkage in SL-RP are derived. By using above conclusions and the commercial FEM(Finite element method)package ABAQUS, the numerical simulation of parts deformation in SL-RP is carried out. The numerical results are well consistent with the experimental ones. That shows that it is reasonable for using temperature stress to simulated the shrinkage of resin phase change and it is appropriate for numerical simulation of parts deformation by using this mechanical equivalent model. So the real deformation forecast of rapid prototyping parts can be performed by using this model.

Key words: Mechanical equivalent model, Phase change shrinkage, Rapid prototyping