Applied Mathematics and Mechanics (English Edition) ›› 1981, Vol. 2 ›› Issue (2): 155-182.

• 论文 •    下一篇

A Physical Model of the Structure and Attenuation of Shock Waves in Metals

段祝平   

  1. Institute of Mechanics, Academia Sinica, Beijing
  • 收稿日期:1980-05-01 出版日期:1981-03-18 发布日期:1981-03-18

A Physical Model of the Structure and Attenuation of Shock Waves in Metals

Duan Zhou-ping   

  1. Institute of Mechanics, Academia Sinica, Beijing
  • Received:1980-05-01 Online:1981-03-18 Published:1981-03-18

摘要: In this paper, a physical model of the structure and attenuation of shock waves in metals is presented. In order to establish the constitutive equations of materials under high velocity deformation and to study the structure of transition zone of shock wave, two independent approaches are involved. Firstly, the specific internal energy is decomposed into the elastic compression energy and elastic deformation energy, and the later is represented by an expansion to third-order terms in elastic strain and entropy, including the coupling effect of heat and mechanical energy. Secondly, a plastic relaxation function describing the behaviour of plastic flow under high temperature and high pressure is suggested from the viewpoint of dislocation dynamics. In addition, a group of ordinary differential equations has been built to determine the thermo-mechanical state variables in the transition zone of a steady shock wave and the thickness of the high pressure shock wave, and an analytical solution of the equations can be found provided that the entropy change across the shock is assumed to be negligible and Hugo-niot compression modulus is used instead of the isentropic compression modulus. A quite approximate method for solving the attenuation of shock wave front has been proposed for the flat-plate symmetric impact problem.

关键词: reliability growth, AMSAA model, AMSAA-BISE model

Abstract: In this paper, a physical model of the structure and attenuation of shock waves in metals is presented. In order to establish the constitutive equations of materials under high velocity deformation and to study the structure of transition zone of shock wave, two independent approaches are involved. Firstly, the specific internal energy is decomposed into the elastic compression energy and elastic deformation energy, and the later is represented by an expansion to third-order terms in elastic strain and entropy, including the coupling effect of heat and mechanical energy. Secondly, a plastic relaxation function describing the behaviour of plastic flow under high temperature and high pressure is suggested from the viewpoint of dislocation dynamics. In addition, a group of ordinary differential equations has been built to determine the thermo-mechanical state variables in the transition zone of a steady shock wave and the thickness of the high pressure shock wave, and an analytical solution of the equations can be found provided that the entropy change across the shock is assumed to be negligible and Hugo-niot compression modulus is used instead of the isentropic compression modulus. A quite approximate method for solving the attenuation of shock wave front has been proposed for the flat-plate symmetric impact problem.

Key words: reliability growth, AMSAA model, AMSAA-BISE model

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