随机参数压电桁架结构的稳定可靠性分析

Reliability analysis of piezoelectric trusses with random parameters

在有限元分析方法基础上,基于稳定特征方程对随机参数压电桁架结构进行稳定可靠性分析.综合考虑电荷载和机械荷载联合作用的机电耦合效应,以杆元的物理参数和外荷载系数为随机变量,给出了压电桁架结构失稳的安全余量的表达形式和临界荷载系数对变量求导的方法.在此基础引入随机有限元法,对压电桁架结构进行结构稳定可靠性分析.最后由算例分析了机电耦合效应压对稳定可靠性指标的影响,分析表明考虑压电材料的机电耦合效应和利用外加电压可以提高结构系统的可靠性指标.该方法对含压电材料桁架在工程实际的稳定可靠性分析提供了一个较好的方法.

The problem of achieving stable reliability analysis of piezoelectric trusses with random parameters was studied on the basis of the finite element analysis method and stable secular equation. Taking into consideration the mechanical-electric coupling effect under electric load and mechanical load, the load coefficient, and the bar section area as stochastic variables, a formula was proposed to determine safety margins of a bar. A stochastic finite element was adopted to analyze the piezoelectric truss stable reliability. The example demonstrated the influence of voltage on a reliability index of the piezoelectric trusses system. The analysis shows that when considering the mechanical-electric coupling effect, the reliability index of a structure system can be enhanced by changing the adscititious voltage. The results indicate this is a preferable method to analyze the stable reliability for actual engineering projects containing piezoelectric trusses.