弹塑性断裂力学COD理论及其在锅炉压力容器安全中的应用

• 作 者: 林宏
• 机 构: 劳动人事部锅炉压力容器检测研究中心,
• 出 处: 锅炉压力容器安全
• 发表日期: 1987年02期
• 关键词: 弹塑性断裂力学 压力容器安全 裂纹尖端 构件 应力断裂 强度设计 许用应力 工程构件 扩展规律 COD

一、引言工程构件的传统的强度设计准则基于许用应力的概念之上,假定材料内部不存在缺陷。然而,人们从大量的事故分析中发现,构件中常常不可避免地带有宏观尺寸的缺陷,研究构件的安全,防止构件低应力断裂,必须从构件带有宏观缺陷的事实出发。在这样的背景下,断裂力学得以诞生并且飞速发展。断裂力学与传统的强度设计有根本的不同,它以带裂纹构件或试件为研究对象,运用弹塑性理论分析裂纹尖端应力应变场,由此进一步分析裂纹的启裂及扩展规律。

I. INTRODUCTION The traditional strength design criteria for engineering components are based on the notion of permissible stress, assuming there is no defect inside the material. However, people from a large number of accident analysis found that the components are often inevitably with macroscopic defects, the study of component safety, to prevent low-stress fracture components must be based on the fact that the components with macro defects. In this context, fracture mechanics was born and rapid development. Fracture mechanics is fundamentally different from the traditional strength design. It takes the cracked member or specimen as the research object and analyzes the stress and strain field of the crack tip by using the elasto-plastic theory to further analyze the crack initiation and propagation.