热环境下长宽比对L型折板统计能量分析参数的影响研究

摘要

基于有限元法和计及热效应的功率输入法,以各边简支的L型折板为研究对象,研究常温和高温环境下长宽比对其统计能量分析参数影响.开展雨流载荷作用下的仿真分析验证统计能量参数获取方法的准确性,开展高温环境下长宽比对模态密度、内损耗因子和耦合损耗因子的影响研究.结果表明:常温环境下长宽比对结构的内损耗因子及耦合损耗因子影响不大;高温环境下长宽比的增加使得结构的耦合损耗因子呈现出先升高后降低的趋势,但对内损耗因子影响不大;两种环境下模态密度均随长宽比的增加而增加.%With the combination of the finite element method (FEM) and the power injection method (PIM)considering thermal effect,a simply-supported L-shaped folded plate was taken as research object to study the influence of aspect ratio on the statistical energy analysis parameters under normal and thermal environments.Firstly,numerical analysis under rain on the roof excitation was studied to verify the accuracy of the proposed method.Then,the effect of aspect ratio on the modal density,the internal loss factor and the coupling loss factor under normal and thermal environments was studied.Results show that the aspect ratio of plate has minor effect on the internal loss factor and the coupling loss factor of the structure under normal environment.Under thermal environment,the coupling loss factor firstly increases and then decreases with the plate aspect ratio.However,the increase of the aspect ratio of plate has little effect on the internal losing factor.The modal density increases with the aspect ratio of plate in both normal and thermal environments.