设计相关动载荷作用下的水下耐压结构拓扑优化

Topology optimization of underwater pressure hull under design-dependent dynamic loading

常规耐压结构拓扑优化设计研究主要集中于静水压条件下的设计相关载荷拓扑优化理论及方法。但是,在深海环境下,耐压结构可能面临内爆所产生的冲击载荷,其载荷呈现高频率的周期性变化。为研究载荷变化对耐压结构优化设计的影响,在BILE模型的基础上,结合修正的SIMP插值模型,开展不同频率、设计相关动载荷作用下的水下耐压结构拓扑优化理论及方法研究。设计相关动载荷的难点在于不仅载荷的作用位置和方向在优化过程中发生变化,且其大小也随优化过程进行而发生变化,这是与常规设计相关静载荷本质的不同。通过经典的拱形结构优化算例验证BILE模型在动力学拓扑优化中的可行性,进而研究设计相关动载荷作用下的水下耐压结构的最佳拓扑形式。研究表明,在低频时,圆环型耐压结构无明显变化,但多球交接耐压结构在交接处会出现明显材料聚集;高频时,两者均发生明显变化,得到耐压结构新形式。关于设计相关动载荷作用下的水下耐压结构拓扑优化研究,将对新型水下耐压结构的探索具有一定的工程应用价值。

The research on the topology optimization design of conventional pressure hull mainly focuses on the topology optimization theory and method of design-dependent loading under hydrostatic pressure.However,in the deep-sea environment,the pressure hull may face the impact load generated by implosion,and its load exhibits high-frequency periodic changes.In order to study the influence of load changing on the optimal design of pressure hull,based on the BILE model,combined with the modified SIMP interpolation model,the research on the topological optimization theory and methods of underwater pressure hull under different frequencies and design-dependent dynamic loads is carried out.The difficulty of design-dependent dynamic load is that not only the position and direction of the load change during the optimization process,but also its magnitude changes as the optimization progresses.This is essentially different from the static load related to the conventional design.First,the feasibility of the BILE model in dynamic topology optimization is verified by a classic arched structure optimization example,and then the optimal topology form of the pressure hull under the design-dependent dynamic load is studied.The research has shown that in the situation of low frequencies,the toroidal pressure hull has no obvious changes,but the multiple intersecting spherical pressure hull will have obvious material accumulation.In the situation of high frequencies,both have significant changes,resulting in a new form of pressure hull.The research on the topology optimization of underwater pressure hull under design-dependent dynamic loads will have certain engineering application value for the exploration of new underwater pressure hull.