APPLICATION OF THE METHOD OF SPLIT RIGIDITIES TO ANlSOTROPIC LAMINATED SHALLOW SHELLS

In this paper,according to the method stated by Hu Hai-chang in [3],on the basis of [1],the method of split rigi-dities is generalized for the purpose of solving the problemsof lateral deflection,stability and lateral vibration foranisotropic laminated shallow shells.and a simple and prac-tical approximate method is obtained.in which the errors andcomputing work are comparatively small.     

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中科院力学所1998年科研工作回顾

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各向异性多层扁壳的大挠度方程

本文在文献[1]的基础上加以改进和推广,探讨各向异性多层扁壳在静载、动载和热载作用下的大挠度方程.考虑了最一般的弯曲拉伸间的耦合关系和沿厚度方向的剪切变形.给出了平衡方程、边界条件和初始条件.得到了以广义位移u₀,v₀,ф_x,ф_y和ω表示的微分方程组.由此可求解应力、变形、稳定和振动等问题.对于若干常见情况,给出了简化的方程和方法.     

纤维增强层合板在单双面压缩下屈曲的优化设计

1979年,日本宇航研究所的Hirano发表了一篇纤维增强层合板铺层角度优化的研究论文。他把与x轴成α_k和—α_k(k表示某一层)方向所铺设的纤维同种、数目相等、基体同一的一个层片定义为一个单层。各个单层之间可以不完全满足单层所定义的条件,这样就考虑到了由N个单层迭合起来的层合板沿厚度方向异质的情况。同时,他还限定各个单层厚度是相等的。每个单层可以取任意的角度。给出层合板的层数,寻求一组铺层角度——各个单层的角度,使临界载荷值最大。由于与迭代起始值有关,他一般是给出8种起始值,然后再从8组结果中挑选临界载荷最大者为最优铺层角度。     

分解刚度法在各向异性多层扁壳理论中的应用

本文按文献[3]中胡海昌阐述的方法,在文献[1]的基础上,将分解刚度法推广应用到各向异性多层扁壳的横向变形、稳定和横向振动问题上去,取得了简单实用、计算工作量和误差都较小的近似计算方法.     

The finite deflection equations of anisotropic laminated shallow shells

In this paper, basing on ref. [1] we improved and extended that which is concerned with a view of investigating the finite deflection equations of anisotropic laminated shallow shells subjected to static loads, dynamic loads and thermal loads. We have considered the most general bending-stretching couplings and the shear deformations in the thickness direction, and derived the equilibrium equations, boundary conditions and initial conditions. The differential equations expressed in terms of generalized displacements u₀, ₀ and are obtained. From them, we could solve the problems of stress analysis, deformation, stability and vibration. For some commonly encountered cases, we derived the simplified equations and methods.     

复合材料的多层、夹层和加筋圆柱曲板的稳定和振动

本文在文献〔1,2〕的基础上,考虑了沿壳体厚度方向的剪切变形,探讨周边简支的纤维增强复合材料的正交各向异性的多层、夹层和加筋矩形圆柱曲板(与圆柱壳),在轴压、侧压和剪切(扭矩)作用下的临界载荷和横向振动固有频率的计算问题。在编成计算程序后,用一些算例将用文献〔1〕中的扁壳方程(Donnell壳体理论) 和文献〔3〕中的非扁壳方程(Love的壳体一阶近似理论) 算得的结果作了比较;将轴压下轴对称失稳和非轴对称失稳的临界载荷作了比较;将在轴压和侧压作用下失稳时外加筋曲板和内加筋曲板的临界载荷作了比较;将有薄膜力N_x~0和N_y~0同时和分别作用时与没有薄膜力作用时的横向振动固有频率作了比较;将按壳体的剪切变形理论和经典理论算得的临界载荷作了比较;将铺层情况对临界载荷的影响作了比较。     

THE FINITE DEFLECTION EQUATIONS OF ANISOTROPIC LAMINATED SHALLOW SHELLS

In this paper,basing on ref.[1]we improved andextended that Which is concerned with a view of inves-tigating the finite deflection equations of anisotro-pic laminated shallow shells subjected to static loads,dynamic loads and thermal loads.We have consideredthe most general bending-stretching couplings and theshear deformations in the thickness direction.and de-rived the equilibrium equations,boundary conditionsand initial conditions.The differential equationsexpressed in terms of generalized displacements u_o,υ_o,φ_x, φ_y and w are obtained.From them,we could solvethe problems of stress analysis,deformation,stabilityand vibration.For some commonly encountered cases,we derived the simplified equations and methods.