一种提高多材料拓扑优化结构安全性和强度的策略

A strategy for improving the safety and strength of topologically optimized multi-material structures

本文介绍了一种用于多材料拓扑优化中分配两种不同材料的新策略.基于单一材料的双向渐进结构优化(BESO)法开发的多材料双向渐进结构优化(MBESO)法能够有效的处理诸如钢-混凝土这种双材料结构的拓扑优化问题.然而,在一些特殊情况下,使用MBESO方法设计的多材料结构中,部分受压材料可能会出现受压超限导致结构不安全的情况.为了解决这种关键问题,本文提出了一种简单而有效的材料分布策略.例如在钢-混凝土结构中,部分压应力过大的混凝土材料可以用钢材替代.在压力最大的局部区域布置少量的钢材可以有效地将混凝土材料的最大压应力降至安全水平.本文通过一系列2D和3D案例的对比研究表明,相比于原始的MBESO方法,改进的双材料分布策略可以有效的解决双材料拓扑优化结构中局部压应力过大的情况,证明了该方法在增强拓扑优化复合结构的安全性方面的有效性,显示出该材料分配策略在多材料拓扑优化研究和应用中的巨大潜力和价值.

This paper presents a new strategy to distribute two different materials for multi-material topology optimization.Extended from the bi-directional evolutionary structural optimization(BESO)method for a single material,the multi-material bidirectional evolutionary structural optimization(MBESO)method has been developed,which can effectively handle the topology optimization problems involving two materials like steel and concrete.However,in some special cases,overloading of part of the compressed material occurs in the multi-material structures designed by using the MBESO method.Aimed to solve this critical problem,a simple but effective strategy is proposed in this paper.In steel-concrete composite structures,for instance,the overloaded compressed concrete elements with exceedingly high stress are replaced with steel material.The small amount of steel material added to the highly compressed region can effectively reduce the maximum compressive stress of the concrete material to a safe level.The comparison between the original MBESO method and the improved strategy based on a series of two-dimensional and three-dimensional examples clearly demonstrates the effectiveness of the proposed strategy in enhancing the structural safety and strength of the topologically optimized composite structures.This distinctly different material distribution strategy shows its potential and value in multi-material topology optimization research and applications.