摘要:
本文的目的并非简单地评述弹性静力学。著名的Cauchy六方程,其命题是由位移函数(ui, uj, uk)=u(xi, xj, xk)的九个偏导数线性表达的,但其逆命题是该六个方程不可能表达阵(∂(ui, uj, uk)/∂(xi, xj, xk))的九个元素,这是由于在给定点上的变形的几何表示至今尚不完全[1]。用几何语言来说,其逆命题的含意就是:在空间中任意三角形(正交除外)边的“平方长”运算用Pythogora's定理的结论是不真的[2]。本文将叙述代数弹性运动的某些数学规律及其与上述问题的关系。
Abstract:
This paper is neither laudatory nor derogatory but it simply contrasts with what might be called elastosiatic (or static topology), a proposition of the famous six equations. The extension strains and the shearing strains which were derived by A.L. Cauchy, are linearly expressed in terms of nine partial derivatives of the displacement function(ui, uj, uk) =u(xi, xj, xk) and it is impossible for the inverse proposition to sep up a system of the above six equations in expressing the nine components of matrix (∂(ui, uj, uk)/∂(xi, xj, xk). This is due to the fact that our geometrical representations of deformation at a given point are as yet incomplete[1]. On the other hand, in more geometrical language this theorem is not true to any triangle, except orthogonal, for "squared length" in space[2].The purpose of this paper is to describe some mathematic laws of algebraic elastodynamics and the relationships between the above-mentioned important questions.