Abstract:

Based on randomness appeared in stiffness, external load and strength of a structure system in applying, an optimized design method of a structure system is proposed by considering random factors. In the method, sensitivity analysis of the system reliability index is first carried out. Then, the reliability index is considered as a constraint function to establish an optimized model and structure weight is optimized. Here, hybrid genetic algorithm of the traditional genetic algorithm combined with the optimal vector method is presented, and the Niche technology is introduced to perform structural optimized design. Analytical results indicate that the hybrid genetic algorithm based on Niche technology not only has the strong local searching capacity of the optimal vector method but also has the strong general searching capacity of the genetic algorithm, so convergence performance is greatly improved. Calculated example indicates that hybrid genetic algorithm based on the Niche technology is a high-effective structural optimized method.

Key words: stochastic structure, reliability, optimization design, genetic algorithm, optimal vector algorithm, niche technology, hybrid genetic algorithm