加筋板在热声载荷作用下的非线性动态响应分析

Nonlinear dynamic response of stiffened plates subject to thermo-acoustic loadings

先进航空航天飞行器为减轻重量而大量采用薄壁结构,随着飞行速度的提高,其面临着的日益严峻的高温强噪声工作环境,会使得薄壁结构在复杂的应力应变状态下产生大挠度非线性响应,严重影响了飞行器的工作可靠性。给出了热声载荷作用下薄板结构的大挠度运动方程,分析了发生热屈曲的临界温度,并运用有限元方法进行数值模拟,分别计算了四边简支薄壁板与加筋板在相同有限带宽高斯白噪声载荷和变化温度下的动态响应,比较了两种结构在相同热声载荷环境下的非线性动态响应特征。

A large number of thin-walled structures have been adopted in advanced aerospace flight vehicles to reduce weight. Because of the increasingly serious working condition, they are subject to combined excita- tion of elevated thermal load and high level acoustic load. It will generate a large deflection nonlinear respon- ses under a complex stress-strain state, and the working reliability of the aircraft will be affected seriously in this case. This paper analyzes the critical loading of thermal buckling base on Von Karman large deflection equation for thin-walled structures. The dynamic response of simply-supported aluminum alloy thin-walled plate and stiffened plate under the same SPL but different temperature has been calculated with FEM. The characteristics of their nonlinear dynamic response have been compared.