旋扭构造的成因类型和演化规律的光弹实验及变形特征分析

EXPERIMENTAL ANALYSES OF GENETIC TYPES AND EVOLUTIONARY REGULARTY OF VORTEX STRUCTURES

应用无限小弹性理论讨论旋扭构造的形成机制,最近几年来已发表了数篇论文。然而,这些讨论都是建立在无限小弹性理论假设的基础上,这种理论的一个显著特点是把应力主轴和应变主轴看作重合的,就是说应力迹线的形态和性质反映了结构面展布的形态和力学性质。因为采用了无限小变形的假设,所以也就不必考虑有限变形和旋转变形问题。但是我们清楚地知道旋扭构造的形成一般都经过了较大的变形,在这种大变形的条件下应力场和应变场之间的关系如何?

Genetic type and evolutionary regularity of vortex structures has been discussed by the author (1982C 3 3) .The purpose of this paper is to introduce the experimental investigtion of vortex shaped structures.The authors make a preliminary discussion on the characteristics of the stress field and the strain field of vorte shaped structures by use of the experimental method. According to photoelas-tic experiments the authors deal with the determination of two dimensional stressfields by use of polarized light and with the determination of strain field py use of the measurements of finite strain. From the analysis of the deformation process and the characteristics under the condition of the finite strain, the existence of the differences in the direction between the principal stress and the principal strain has been obtained. Futhermore the evolutionary regularity of radial-vortex-ring shaped structures under the conditions of strain and the infinitesimal strain can be found in terms of the exprimental method.