CONTINUUM STRUCTURAL TOPOLOGY OPTIMIZATION WITH GLOBALIZED STRESS CONSTRAINT TREATED BY STRUCTURAL DISTORTIONAL STRAIN ENERGY DENSITY

The stress constraint is replaced by the distortional strain energy density constraint because the von Mises strength criterion was essentially established on the distortional strain energy density. According to stress globalization strategy, the concept of a structural distortional strain energy density constraint is defined and it is applied to sharply reduce stress constraints in solving a structural topology optimization problem with least weight subjected to stress constraints. A parameter-power function about the ratio of allowable stress to maximum stress in the structure is constructed to modify the constraint limit dynamically. Based on ICM (Independent Continuous and Mapping) method, an exponential-class fast filter function is adopted to present a structural topological optimization model, and then the model is solved by sequential quadratic optimization based on exact dual mapping. The numerical examples demonstrate that the approach of adopting globalization strategy of modified structural distortional strain energy density to deal with the structural topological optimization problem with stress constraints is available and efficient. The method proposed in the paper is also useful to solve the loading illness problem between different loading cases.