A novel design method based on proportional periodic topology optimization and its application in box metal structures

To reduce self-weight and energy consumption, a novel proportional periodic topology optimization approach for box-shaped metal structures is developed. The key to the method is changing the proportion of optimization domains in different subdomains. Proportional periodic topology optimization mathematical models for continuous dimensions are established as a foundation. To reduce machining difficulty caused by continuous dimensions, an optimization algorithm based on the optimal discrete dimension is created. In periodic topology optimization, the number of subdomains influences the results and efficiency. Therefore, a formula to calculate the optimal number of subdomains is created, and optimization is conducted based on this optimal number. When the optimal number is a non-integer, the subdomain half-processing method is proposed. The proportional periodic topology optimization method is applied in the topology optimization of a crane arm. The results demonstrate that the proposed method is effective in reducing machining difficulty, improving mechanical performance and achieving a lightweight structure.