一种基于应力的双方向结构拓扑优化算法

基于传统的渐进结构优化方法，提出了一种基于应力的双方向渐进拓扑优化算法。该方法是对传统方法和目前的双方向法的改进和完善。算例表明该方法能避免目前的双方向法具有的解的振荡问题，具有更高的可靠性，能获得更佳的拓扑结构。

A bi-directional algorithm of structural topology optimization

The evolutionary structural optimization (ESO) method has been under continuous deve-lopment since 1992. Originally the method was conceived from the engineering perspective that the topology and shape of structures were naturally conservative for safety reasons and therefore contained an excess of material. To move from the conservative design to a more optimum design would therefore involve the removal of material. The ESO algorithm caters for topology optimization by allowing the removal of material from all parts of the design space. With appropriate chequer-board controls and controls on the number of cavities formed, the method can reproduce traditional fully stressed topologies, and has been applied into the problems with static stress, stiffness, displacement etc. constraints. If the algorithm was restricted to the removal of surface-only material, then a shape optimization problem is solved. Recent research (Q.M. Quern) has presented a bi-directional evolutionary structural optimization (BESO) method whereby material can be added to and removed off. But there are much more oscillation states in optimizing iteration processes of this BESO method, it leads to long calculation time for an optimum solution. In order to improve this BESO method, in this paper, based on stresses and the evolutionary structural optimization method, a procedure for an improved bi-directional structural topology optimization is given. It is a development and modification of the conventional ESO and the BESO method. Two examples demonstrate that the proposed method can deal with the solution oscillatory phenomenon, and obtain more optimal structural topology, and is of higher reliability.