Model Bolting Conditions 1 / R Deflection Invar 36 Deflection 1117 steel

Layered Manufacturing processes accumulate residual stresses during material build-up. These stresses may cause part warping and layer delamination. This paper presents work done on investigating residual stress accumulation and part distortion of Layered Manufactured ar-tifacts. A simple analytical model was developed and used to determine how the number of layers and the layer thickness influences part warping. Results show that thin layers produce lower part deflection as compared with depositing fewer and thicker layers. In addition to the analytical work, a finite element model was developed and used to investigate the deposition pattern's influence on the part deflection. Finite element model and corresponding experimental analysis showed that the geometry of the deposition pattern significantly affects the resulting part distortion. This finite element model was also used to investigate an inter-layer surface defect, known as the Christmas Tree Step, that is associated with Shape Deposition Manufacturing. Results indicate that the features of this defect are influenced only by the material deposited close to the part surface and the particular material deposited. The step is not affected by the deposition pattern.