金属材料断裂与应力状态参数的关系

罗德参数、软性系数和应力三维度是研究金属材料变形、破坏时常用的应力状态参数,分析从三向压缩到三向拉伸不同应力状态下各参数值的变化,得出:应力三维度值从小向大有规律地变化,罗德参数和软性系数则不能分析裂纹体、无裂纹体金属材料断裂破坏的试验结果;同时认识到构件中,体积变形较大、形状变形较小处是材料发生脆断、准脆断的断裂萌生点,此危险点正是应力三维度有较大值处。

The Relation Between Fracture of Metal Material and Stress State Parameter

Rod parameter,soft coefficient and stress triaxiaty,are the commonly-used stress state parameter in studying the deformation and fracture of metal material.This paper analyses the change law of every parameter value under different stress states from three dimension compression to three dimension tension,and then,several conclusions can be drawn:the stress triaxiaty value changes from small to large regularly,and Rod parameter and soft coefficient can not be used to analyse the testing results of fracture and damage of cracking body and cracking-free body metal materials;and at the same time,it is realized that the larger volume deformation and smaller shape deformation are the fracture emerging points where the brittle fracture and sub-fracture of metal materials frequently occure.