Incorporating draw constraint in the lightweight and self-supporting optimisation process for selective laser melting

Abstract

Due to the manufacturing ability of selective laser melting (SLM) in complex lightweight structures resulting from topology optimisation (TO), SLM and TO are considered to be the best combination. However, support structures are required for SLM processes because of the very complex lightweight structures resulting from TO. Support structures also help resist the thermal stress which can damage the part. On the other hand, support structures have some shortcomings including the difficulty of removing them from the original part and the increases in the total cost and manufacturing time. Because of the above-mentioned deficiencies, more research will be conducted in the near future to investigate the design of self-supporting components for SLM technology. Therefore, this study proposes a new design method, called topology optimisation design with draw constraint (TODDC). The proposed method can simultaneously realise lightweight and self-supporting design for SLM processes. The detailed design process is presented and its advantages are discussed. The most significant advantage of the proposed method is that topology optimisation will be the final design tool not only for the conceptual design but also for the industrial component. TO is applied in the design process to reduce weight and draw constraint is imported into the TO process to meet the self-supporting requirement. As for the industrial implications of the research, a control arm component is designed using the proposed method, and the final model is produced successfully using the SLM technology. Thus, the effectiveness of the proposed method in designing lightweight and self-supporting industrial metal components for SLM processes is verified through the case study.