对于运载飞行器一类由多个部段装配而成的复杂结构,外载荷往往被转化为多点集中载荷传递到结构某一部段,为此,结构上需要采取使集中力扩散的措施.基于连续体拓扑优化,以结构最小柔顺性为目标函数,同时考虑设计域内材料用量约束和考查区域(承载结构)内力均匀性约束,提出了集中力扩散结构优化设计的理论模型,并给出了平面和三维两种不同的优化算例,均得到了合理的优化设计结果.最后,针对运载火箭燃料贮箱短壳,考虑工程实际的受力及约束情况,给出了可行的概念性设计方案.
For complicated structures assembled by several parts, like launch vehicle, external load in the form of concentrated load exerted on several points is transmitted to a given section of the structure. Therefore, some measures should be taken in the structural design to diffuse the concentrated force. In order to optimize the structure for diffusing the concentrated force, a theoretical model based on the continuum topology optimization is presented in this paper. The minimum structural compliance is taken as the object function subject to structural materials' volume constraint. Constraints on uniformity of the internal force are also considered in this model. Two-dimensional and three-dimensional examples are presented to illustrate the effectiveness of the formulation and algorithm. Finally, based on the actual forces and displacement constraints, a feasible conceptual design is presented for the short shell of a rocket's storage trunk.