Stability and Large Deformations in Structural Optimization

摘要

The present contribution focuses on the influence of geometrical non-linearities on the structural behavior in the design process. The notion of the stiffest structure loses its clear definition in case of nonlinear kinematics; here we will discuss this concept on the basis of three different objectives. Apparently topology optimization is often a generator of slender struts, which tend to buckle before the structure is completely loaded. To include the instability phenomena into the design process the critical load level will be determined directly; this condition will be included as an inequality constraint. Further on in order to reduce the imperfection sensitivity a geometrically modified structure including the imperfection shape is introduced in addition. The present optimization procedures are demonstrated by examples showing rather the principle effects of the enhancements than real practical design problems.