基于参数化有限元的深潜器主框架优化设计

深潜器主框架是一个大型空间刚架结构,如何对这类复杂的工程结构进行优化,使其既满足自身的强度和刚度要求,同时又满足总体设计对主框架重量和布置的要求,这些仅仅根据经验是不够的,如何充分利用现有的大型通用有限元软件的优化设计功能显得尤为重要.本文利用现有通用大型有限元软件MSC Patran/Nastran,基于参数化设计的思想,对深潜器主框架进行了两个方面的优化设计:首先在初步设计方案的基础上,应用有限元静力分析功能,对方案进行渐进结构拓扑优化;其次,对选定的方案,分别采用可行方向法、序列线性规划法和序列二次规划法这3种优化算法对主框架进行优化,并比较各优化方法的适用性,说明了对于复杂结构存在的目标函数多峰值现象.结果表明,通过参数驱动有限元优化能够显著减轻主框架的整体重量,使材料达到最大的利用效率,具有实用意义.

Variable - drive finite element method based optimal design for the main frame of deep manned submersible

The main frame of a deep manned submersible is a complex space rigid frame.It is designed as a structure to install a manned pressure hull,batteries,electric inverters and a distributor,main ballasting tanks,buoyancy materials and so on.It is not enough to design based only on experience,thus it is essen - tial to develop and apply the optimization method to the present large scale complex structures.On the ba - sis of the design consideration and applying the variable drive modeling method,this paper mainly de - scribed the optimization of the main frame on two aspects by the FEA software-MSC Patran/Nastran.One was using the static analysis function to optimize the preliminary schemes by the Evolutionary Structural Optimization method.After the first level optimization,the paper went on to the size optimization using the following three methods:modified method of feasible directions,sequential linear programming and se - quential quadratic programming.The results indicate that the weight of the main frame structure can be further reduced and the optimization methods presented in this paper are reliable and practical for the op - timal design of engineering structures.This paper also demonstrates the phenomena of multi-peak value of the objective function due to the complicated structure and its nonlinear.