1Cr18Ni9Ti管材拉伸试验及断口形成的有限元分析

Tensile Tests and Finite Element Analysis of the Fracture Formation of 1Crl8Ni9Ti Tube

目的研究管材在单向拉伸失稳过程中的应力应变分布及断口形状。方法在1Cr18Ni9Ti管材轴向拉伸试验的基础上,利用ABAQUS进行了拉伸全过程的有限元模拟分析。结果管材拉伸失稳阶段,细颈区内侧壁附近三向主应力均大于相应的外侧壁主应力;初始裂纹率先产生在内侧壁表面附近的某一区域。结论 1Cr18Ni9Ti管拉伸断裂具有剪切断裂倾向,多数试样断面与拉伸轴倾斜约±45°,拉裂裂纹从内侧壁附近开始向外侧壁扩展,最终断裂线往往不在同一平面上。

ABSTRACT:In order to investigate the stress and strain distribution and shape of the fracture in the instability process of the pipes under uniaxial tension load,finite element analysis for whole process of uniaxial tension for the tube was carried out based on a series of experiments on axial tensile of 1Cr18Ni9Ti tube.During the instability process of the tube,three principal stress close to the inner tube wall were greater than the corresponding principal stress of the outer wall. Initial crack firstly occurred in the area which was close to the inner tube wall.The fracture of tube under uniaxial tension has a tendency to shear fracture,which forms a degree of plus or minus 45 ° between fracture section and tensile axis,and crack forming close to the inner tube wall gradually propagates to the outer tube wall,so the final crack lines are often not in the same plane.