基于 iSIGHT 的风洞应变天平优化设计方法研究

摘要

天平设计的关键在于天平结构的优化，在满足设计要求的前提下，尽量提高天平刚度，避免应力集中，减小各测量分量之间的相互干扰，以提高设计质量。天平优化设计是一个多目标问题，无论利用解析方法还是有限元仿真方法，设计分析过程通常需要丰富的经验，即使耗费大量时间也很难获得全局最优解。以6分量杆式应变天平为研究对象，提出了分级和分步优化策略，介绍了基于 iSIGHT 平台的实现方法。通过试验设计（DOE）筛选出对优化目标影响较大的设计变量，然后建立天平优化设计近似参数化模型。在 iSIGHT 中通过集成 UG、AN-SYS 和 EXCEL 等软件建立自动优化流程。以参数化三维结构有限元仿真分析方法为基础，利用 iSIGHT 提供的优化算法，实现优化设计自动化，大大节省了设计成本，提高了天平设计质量和效率。%The main point of strain gauge balance design is to optimize the configuration of the balance.With the design requirements fulfilled,it is optimal to increase the stiffness,reduce the stress concentration and diminish the interactions among the components in order to improve the quality of the balance.The current trend of balance optimal design is to utilize methods such as perpendicular calculation design method,sequence quadratic optimization method,genetic algo-rithm optimization method,etc,and conduct simulation via MathCAD,Matlab,VC++,AN-SYS,etc.Balance optimal design is a multi-objective optimization design problem.Abundant empirical experiences are required in utilizing both the analytical method and the finite element method (FEM),but still the global optimal solution is hard to obtain.Considering the relations between the dimensions and geometries of various balance configurations,layered and parallel op-timal strategies are proposed.An optimal design method for the wind tunnel strain gauge rear-sting balance with six components based on iSIGHT is introduced.The significant effects of bal-ance design variables to the optimal objective are studied by design of experiment (DOE)so that a set of important variables are selected to set up an approximate 3D parameterized model.The parametric modeling method and the finite element method are applied.An optimization flow is automatically running in iSIGHT by integrating many design tools such as UG,ANSYS,EX-CEL,etc.General optimal algorithms are provided by iSIGHT and a lot of commercial software can be integrated to support the automatic running.This method offers an economical and easy way to improve the balance design quality.