Development of Thermal and Structural Deformation Model to Predict the Part Build Dimensional Error in Fused Deposition Modeling

The most common extrusion based technology in rapid prototyping is Fused Deposition Modeling (FDM). In FDM process, widely used materials are Acrylonitrile Butadiene Styrene (ABS) and Polycarbonate. In this study ABS-P۴۳۰ material is considered. During the part build process, the rapid heating and cooling is happening on the build part which leads to high thermal gradient. This thermal gradient causes thermal stress; it will lead to deformation of build parts. In this paper a three dimensional transient thermo-mechanical Finite Element Analysis (FEA) had been used to find out the maximum principal stress and deformation of the build part. This FEA analysis is called as thermal and structural deformation model or ۳D FEA model. In this model, the novel technique called Element birth/death is used in ANSYS۱۱ to mimic the FDM process. The most influencing parameters of FDM process called orientation and layer thickness have been considered in a ۳D FEA model to calculate the deformation of a part. To validate the work, a standard design which is considered in ۳D FEA model is fabricated using dimension ۱۲۰۰es FDM machine using same orientation and layer thickness and deformation is measured. From the results it was observed that the relative error between ۳D FEA model and actual fabricated model is found to be ۳-۶%. This ۳D FEA model would be helpful for RP machine users to find the deformation of the build part before making the products.

Keywords:

deformation , Deformation model , Fused deposition modeling , Thermal and structural element birth/death function