Determination of the optimal part orientation in layered manufacturing using a genetic algorithm

Several important factors must be taken into consideration to maximise the efficiency of rapid prototyping (RP) processes. The ability to select the optimal orientation of a build direction is one of the most critical factors in using RP processes, since it affects the quality of the prototyped part, the support structure and the build time. This study aims to determine the optimal part orientation that improves the average weighted surface roughness generated from the stair stepping effect. It also minimises the build time including the structure of the support in fabricating a completely freeform part. To avoid pre-selection operation, which is often troublesome and time-consuming, the genetic algorithm, that considers the fuzzy weight for surface roughness and build time, is used to determine the optimal orientation. The validity of the proposed algorithm is demonstrated by several examples using different RP systems and compared with previous works. The algorithm can help RP users select the best orientation of the part and carry out efficient process planning.