三维计算断裂力学

断裂力学理论从1921年Griffith研究玻璃的脆性断裂问题开始,经历了从线弹性体系到弹塑性以及蠕变理论体系、从单参数到多参数体系和从理想的二维平面理论到实际三维含裂纹结构的三维断裂理论的发展历程。针对应力强度因子K和J积分以及C(t)积分的计算方法从理想化模型的理论计算发展到实际复杂工程结构裂纹体计算的各种商业软件平台以及专业的断裂理论分析平台。尤其是随着计算机技术的发展,对三维含裂结构的静态和扩展裂纹的计算模拟已经能够融入计算机辅助设计。结合本研究组近30年来在三维疲劳断裂理论和应用研究方面的体会,简述了三维计算断裂力学从裂纹体应力应变分析和断裂参数计算到三维蠕变断裂和疲劳裂纹扩展模拟的国内外进展,并对涉及的计算方法,包括原子尺度和跨尺度的计算模拟,以及目前面临的挑战性问题作了简要介绍和分析。

Computational mechanics of three-dimensional fracture

Since Griffith conducted the study of brittle fracture of glass in 1921,the theory of fracture mechanics has experienced progress from linear elastic solids to elastic-plastic materials and creep theory,from single parameter to multi parameter systems and from the ideal two-dimensional plane theory to the theory of practical structures containing three dimensional(3D) cracks.Calculation methods aiming at stress intensity factor K,J-integral and C(t) integral have evolved from the theoretical calculation of idealized models to series of commercial software platforms of solving crack-calculation problems of actual complex engineering structures and professional platforms of fracture theory analysis.Especially with the development of computer technology,the calculations and simulations of the static and expanding crack of the 3D crack structures are integrated into the computer aided design.In this paper,with our experience in developing the 3D fatigue fracture theory and application in the past thirty years,we briefly describe the development of 3D computational fracture mechanics from the stress and strain analysis of the crack body,the calculation of fracture parameters to the simulation of 3D creep fracture and fatigue crack growth in both China and abroad.Finally,a brief introduction and analysis of the computational methods involved,including atomic scale and multi-scale computational simulations,along with some personal perspectives on the challenges and future research directions,are presented.