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1.
一般旋转壳在轴对称变形下的复变量方程   总被引:1,自引:1,他引:0  
本文在Love-Kirchhoff的假定下,求得了一般旋转壳在轴对称变形下的复变量方程.当旋转壳是圆截面环壳时,这些方程简化为F.Tlke(1938),R.A.Clark(1950)和B.B.HOBOm~JIOB(1951)的方程.当平均半径(?)比环截面半径a大得很多时,求得了细环壳的复变量方程,当这个细环壳的截面是圆形时,简化作为作者(1979)的圆截面的细环壳复变量方程,我们列出了椭圆截面的细环壳复变量方程.当椭圆截面近似于圆截面时,该方程在形式上和圆细环壳方程基本相同.  相似文献   
2.
AFURTHERSTUDYOFTHETHEORYOFELASTICCIRCULARPLATESWITHNON-KIRCHHOFF-LOVEASSUMPTIONSChienWei-zang(钱伟长)RuXue-ping(茹学萍)(ShanghaiUni...  相似文献   
3.
本文给出了圆薄膜中心部份受均布载荷产生的对称弯曲变形的解,它的极限给出圆薄膜在中心集中载荷下的解.它们是Hencky圆薄膜解以后,第三种有关的圆薄膜解.  相似文献   
4.
关于线性三角形单元精确刚度矩阵的计算,确实存在有不收敛的项,但是与这些项相对应的行列,最终都是要处理掉的.因为这些项只发生于节点在对称轴上的时候,而此时总有u_i=0,因此只需在程序编制上预先作一次判断就行.我曾作过大量的精确矩阵的计算,结果表明是良好的.Zienkiewicz的错误结论,主要在于Ⅰ_1的错误公式,从而引起计算结果偏离实际.  相似文献   
5.
Based on generalized variational principles,an element called MR-12 was constructed for the static and dynamic analysis of thin plates with orthogonal anisotropy.Numerical results showed that this incompatible clement converges very rapidly and has good accuracy.It was demonstrated that generalized variational principles are useful and effective in founding incompatible element.Moreover,element MR-12 is easy for implementation since it does not differ very much from the common rectangular element R-12 of thin plate.  相似文献   
6.
The present paper is addressed to the finite element method combined with dynamicphotoelastic analysis of propagating cracks,that is,on the basis of[1]by Chien Wei-zang,finite elements which incorporate the propagating crack-tip singularity intrinsic to two-dimensional elasticity are employed.The relation between crack opening length and timestep obtained from dynamic photoelastic analysis is used as a definite condition for solvingthe dynamic equations and simulating the crack propagations as well.As an example,theimpact response of dynamic-bending-test.specimen is investigated and the dynamic stress-intensity factor obtained from the mentioned finite element analysis and dynamicphotoelasticity is in reasonable agreement with each other.  相似文献   
7.
柱形弹体撞击塑性变形的G.I.泰勒理论的分析解及其改进   总被引:1,自引:0,他引:1  
柱形弹体对刚性靶体的纵向撞击塑性变形理论是G.I.泰勒首先提出的.这个理论的重要性在于通过这个理论可以从实验数据计算动力屈服强度,而且从实验结果中看到,动力屈服强度和撞击速度无关,动力屈服强度高于静力屈服强度,对某些材料而言,可以超出好几倍.这样就为弹塑性撞击研究提供了一个重要的根据.但是,泰勒理论由于微分方程的复杂性,求解过程都是数值计算,这样对使用其结果时深感不便.本文提供了全部分析解,并对其结果进行了讨论.本文对冲量计算进行了修正,修正理论的分析解指出,其结果比泰勒理论的解更加符合实验.  相似文献   
8.
In this paper, variational principels in elasticity are classified according to the differences in the constraints used in these principles. It is shown in a previous paper that the stress-strain relations are the constraint conditions in all these variational principles, and cannot be removed by the method of linear Lagrange multiplier. The other possible constraints are four of them: (1) equations of equilibrium,(2) strain-displacement relations, (3) boundary conditions of given external forces and (4) boundary conditions of given boundary displacements. In variational principles of elasticity, some of. them have only one kind of such constraints, some have two kinds or three kinds of constraints and at the most four kinds of constraints. Thus, we have altogether 15 kinds of possible variational principles. However, for every possible variational principle, either the strain energy density or the complementary energy density may be used. Hence, there arealtogether 30 classes of functional of variation  相似文献   
9.
There are some common difficulties encountered in elastic-plas-tic impact codes such as EPIC,NONSAP etc.Most of thesecodes use the simple linear functions usually taken from static pro-blems to represent the displacement components.In such finite ele-ment formulation,the strain and stress components are constants inevery element.In the equations of motion,the stress components ingeneral appear in the form of their space derivatives.Thus,if weuse such form functions to represent the displacement components,the effect of internal stresses to the equations of motion vanishesidentically.The usual practice to overcome such difficulties isto establish as self-equilibrium system of internal forces actingon various nodal points by means of transforming equations of mo-tion into variational form of energy relation through the applica-tion of virtual displacement principle.The nodal acceleration.isthen calculated from the total force acting on this node from allthe neighbouring elements.The transformation of virt  相似文献   
10.
本文用合成展开摄动法,把外场解和内层解结合起来,求解圆薄板大挠度问题.本文把Hencky的薄膜解当作外场解的一级近似解,并求出了外场解的二级近似解.利用边界内层坐标,求得了相应的各级内层解,即边界层解.本文采用最大位移和板厚之比的倒数作为小参数,所得结果大大改进了1948年作者所得的结果.  相似文献   
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