Joints for treelike column structures based on generative design and additive manufacturing

Joint design is always of particular interest and important to treelike column structures in view of their structural integrity and cost. In this work, an integrated method based on generative design and additive manufacturing is presented to obtain an optimal joint structure. This method is applied to design a three-branch joint, and hundreds of models are automatically generated from a cloud computing platform. Then, two representative joint models with the lowest mass are selected for further static behavior analysis. Furthermore, the analysis results are compared to three other types of joints, namely the topologically optimized joint generated by Optistruct software, the hollow spherical joint commonly used in engineering applications and the bionic joint developed by simulating a branching plant in nature. Finally, reduced-scale models of the above joints are produced by the additive manufacturing technique using both polylactic acid plastic and stainless steel. The effects of parameter settings and support methods on the quality of additive manufacturing are discussed. The results show that the representative joints obtained by the generative design exhibit more uniform stress distribution and better static behavior than the other joints. Additive manufacturing technology can not only improve the accuracy of joint production but also solve the key problem that complex shapes formed by generative design are difficult to be produced by traditional processes. Thus, it is effective and promising for combine generative design with additive manufacturing to design and manufacture joints for treelike column structures.