基于有限元的车体材料301L-DLT冷轧不锈钢断裂分析  

Fracture Analysis of Carbody Material 301L-DLT Cold-Rolled Stainless Steel Based on Finite Element

作　　者：卢翀 曹玉 黄健 高福来 LU Chong;CAO Yu;HUANG Jian;GAO Fulai(Standards&Metrology Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;China Railway Test&Certification Center Limited,Beijing 100015,China)

机构地区：[1]中国铁道科学研究院集团有限公司标准计量研究所,北京100081 [2]中铁检验认证中心有限公司,北京100015

出　　处：《中国铁道科学》2021年第5期146-154,共9页China Railway Science

基　　金：中国铁道科学研究院集团有限公司院基金课题(2020YJ155)。

摘　　要：以轨道车辆车体的主要材料301L-DLT冷轧不锈钢为研究对象,设计无缺口及2和4 mm缺口3种拉伸断裂试样,对其进行不同应力状态下的拉伸断裂试验,并进行断口形貌观察;依据试验结果,采用有限元方法研究301L-DLT冷轧不锈钢在不同应力状态下的损伤和断裂机制;分别建立基于G-T-N(Gurson-Needle⁃man-Tvergaard)与J-C(Johnson-Cook)断裂理论的断裂模型,对断裂试验过程进行数值模拟,并将其结果与试验结果进行对比。结果表明:尽管试样缺口处的宽度相同,但由于缺口处形状的不同,301L-DLT冷轧不锈钢的断裂塑性应变随着应力三轴度的增大从1.41下降至0.78;基于G-T-N断裂理论与J-C断裂理论的301L-DLT冷轧不锈钢断裂模型,均较好地重现了韧性断裂过程,为准确预测车体碰撞断裂的过程提供基础。Taking 301L-DLT cold-rolled stainless steel,the main material for the carbody of railway vehicle,as the research object,three kinds of tensile fracture specimens with no notch,2 mm and 4 mm notches were designed.The tensile fracture tests were carried out under different stress states and the fracture morphology was observed.Based on the test results,the finite element method was used to study the damage and fracture mechanism of 301L-DLT cold-rolled stainless steel under different stress states.The fracture models were established based on G-T-N(Gurson-Needleman-Tvergaard)and J-C(Johnson-Cook)fracture theories respectively.The fracture process was numerically simulated and the results were compared with those of tests.The results show that although the widths at the notches of specimens are the same,the fracture plastic strain of 301L-DLT cold-rolled stainless steel falls from 1.41 to 0.78 with the increase of stress triaxiality due to the different shapes of notches.The fracture models of 301L-DLT cold-rolled stainless steel based on G-T-N fracture theory and J-C fracture theory both can reproduce the ductile fracture process well,which provide a basis for accurately predicting the process of carbody collision fracture.

关 键 词：车体材料 冷轧不锈钢 应力三轴度 韧性断裂 应力状态 

分 类 号：U214.8[交通运输工程—道路与铁道工程]