热冲击下四边简支浅壳的动态突跳行为  

Dynamic snap-through of shallow shells under thermal shock

作　　者：孙伟 何利文 SUN Wei;HE Liwen(Faculty of Mechanical Engineering&Mechanics,Ningbo University,315211 Ningbo,China)

机构地区：[1]宁波大学机械工程与力学学院,宁波315211

出　　处：《应用力学学报》2024年第3期621-628,共8页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.12072168)。

摘　　要：准确地分析和预测浅壳结构在热冲击下的动态稳定性和结构完整性,对于工程中普遍使用的壳结构的设计和优化具有重要意义。利用非线性浅壳理论,并使用Ritz法和Newmark直接积分法研究了内表面受热冲击作用的四边简支各向同性浅壳的动态突跳(snap-through)行为。分析结果表明:浅壳在足够强的热冲击下会发生动态突跳,而在突跳前后都会发生较剧烈的热振动;Budiansky-Hutchinson准则可用于判定发生动态突跳的临界热冲击条件。The dynamic snap-through behavior of isotropic shallow shells under thermal shock loading was studied in the present work.The transient heat conduction through the thickness of shell was analyzed first;the thermally induced membrane forces and bending moments were also derived.The classical shell theory was adopted to model the shell and the derived equations of motion accounts for the Karman's geometrically nonlinear strain.The equations of motion were then transformed into coupled time-dependent nonlinear algebraic equations via the Ritz method,and the latter was numerically solved with the Newmark method and Newton-Raphson's iterative method.The critical thermal shock condition for the occurrence of dynamic snap-through was identified by the Budiansky-Hutchinson criterion while the computational results were analyzed.It was demonstrated that dynamic snap-through occurs in the shallow shell subjected to strong enough thermal shock,and thermally induced vibration exists during the whole snap-through process.The modeling and analysis methods provided by this study have important reference value for accurately evaluating the stability and dynamic response of engineering shallow shells under thermal shock.

关 键 词：热冲击 浅壳 突跳 Budiansky-Hutchinson准则 

分 类 号：O32[理学—一般力学与力学基础]