自第二次世界人战以来,随着高强材料和大型工程结构广泛应用,一些按传统强度理论和常规设计方法设计、制造并经严格检验合格的产品,先后发生了不少灾难性的断裂事故,并且多是在工作应力远低于屈服强度的条件下发生的脆断。用传统的“安全设计观点”无法解释,而大量断裂事故 Since the Second World War, with the extensive application of high-strength materials and large-scale engineering structures, some products that have been designed and manufactured according to the traditional strength theory and conventional design methods and have been rigorously tested have caused many catastrophic failure accidents , And mostly in the working stress far below the yield strength of the brittle fracture occurred. With the traditional “safety design point of view” can not be explained, but a large number of broken accident