Bionic topology optimization design and multi-objective optimization of guide arm

Lightweight design is universally recognized as a critical criterion for many engineering problems. In addition to the well-developed topology optimization (TO) method, structural bionics is also considered an effective approach to developing innovative structure designs with lightweight. In the process of natural evolution, bamboo has developed a unique hollow structure with ingenious mechanical properties. Inspired by these characteristics, this paper selected bamboo as a bionic prototype to carry out bionic structure optimization of guide arm. First, the initial guide arm was modeled and simulated for its mechanical behavior. Secondly, similarity analysis between bamboo and guide arm was performed from three aspects, and the parametric bionic guide arm model was established step by step. Then, the key parameters affecting the performance of the bionic guide arm were verified by the parameter sensitivity analysis method. The multi-objective optimization was carried out with the minimum of the total mass and the maximum deformation of guide arm as the optimization objectives. The optimal solution of Pareto solution set was determined by multi-objective decision methods of the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) and Gray Relational Analysis (GRA). Finally, finite element (FE) method was used to make a comparison between the initial model and the optimal bionic model in terms of mechanical performance. According to the results, under the premise of the mass of the optimized bionic model decreased by 17.44%, the maximum deformation was decreased by 9.24%, the equivalent stress was decreased by 17.33%, and the first-order frequency was increased by 22.92%. Comparison results showed that the proposed bionic model provided the best lightweight solution for guide arm. This study reveals that structural bionics provides a new solution for the lightweight design of guide arm and similar beam structural components.