基于灵敏度分析的桁架结构动力学尺寸优化

Dynamic size optimization of truss based on sensitivityanalysis

以桁架结构杆件截面尺寸参数为设计变量,以结构重量为目标函数,以结构的固有频率为约束条件,建立桁架结构的动力学尺寸优化设计数学模型.通过推导固有频率和结构重量对杆件截面尺寸的灵敏度,确定优化杆件及优化步长,建立了结构尺寸优化设计方法并制定了在ANSYS软件中的实现方案.方法能有效地改变结构固有频率,避免处于动载荷作用下的结构因发生共振而破坏.最后,使用数值算例验证了优化方法的有效性.

Using the section size as design variable, truss weight of truss as objective and natural frequency as constraints, the mathematical model for dynamics size optimization design of truss structure is established. Based on the mathematical model, the sensitivity of natural frequency and structural weight to section size is deduced and thus the members to optimize and their optimization step length is determined. These make up the truss size optimization method, which is then accomplished in the ANSYS software. The method can prevent structures from resonance breakage by adjusting the natural frequency efficiently. Finally this truss size optimization method is illustrate by an example.