热应力作用下结构声-振耦合响应数值分析

摘要

When flying at high speed, material properties, stress state and structure configuration of the aircraft will be changed under high temperature environment caused by serious aerodynamic heating. In this condition, the performance of aircraft during working period may be quite different from design performance. This paper presents a numerical research on the vibro-acoustic response of aircraft under thermal environment. The influence of thermal stress on dynamic characteristics is studied. The finite element equations which consider stress-stiffness effects are formed for vibro-acoustic dynamic analysis. Numerical results show that thermal stress has greater effect on higher order modes and influences the response peak.%考察飞行器结构热应力对结构及其内声腔声-振耦合特性的影响，建立考虑热应力因素的声-振耦合动力学有限元方程，对一个典型飞行器结构考虑热应力时的声-振耦合动力学响应进行分析。计算结果表明，热应力的存在对耦合模型的固有频率影响较小，受热应力影响较大的区域主要集中在机头及机身等部位，其固有振动特性有较明显的变化。通过对比结构加速度与内声腔声压级的响应结果发现，热应力的影响主要表现为系统响应幅值及峰值位置的改变。