高强钢广义屈服和破坏理论

结合经典强度理论和现代损伤力学对金属屈服和断裂解释的力学原理,给出了高强钢在应力三轴空间广义屈服轨迹方程的新诠释.根据三向等拉伸应力状态下高强钢屈服和宏观脆断的重合性,提出了高强钢在应力三轴空间的开裂准则.通过对高强钢刻痕杆断裂试验的数值模拟分析,对比验证了该开裂准则的普适性及精度.最后,给出了高强钢广义强度理论的物理解释及抗断设防.建议的广义强度理论是解高强钢裂纹体和无裂体断裂的一个尝试.

GENERALIZED YIELD AND FRACTURE THEORY OF HIGH STRENGTH STEEL

By combining the classical strength theory with the modern damage mechanics,a new annotation of generalized yield of high strength steel in stress triaxiality space was presented.On the basis of identity of yield and brittle fracture of high strength steel in tri-axial symmetrical stress field,this paper deduced crack criterion in stress trixiality space.By comparing the results of numerical simulations and fracture experiments of notched bars,the effectiveness and accuracy of the crack criterion were verified.A mechanical explanation of the generalized yield and crack model of high strength steel was made.The generalized yield and crack model was an attempt to solve high strength steel fracture of crack and uncrack body.