建筑钢材GTN损伤模型参数识别  

Identification of GTN micromechanical damage parameters of structural steel

作　　者：邢佶慧[1] 史一剑 刘文涛[1] 杨庆山[1] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]中国建筑股份有限公司技术中心,北京101300

出　　处：《建筑结构学报》2014年第4期149-154,共6页Journal of Building Structures

基　　金：国家自然科学基金面上项目(51278036);中国铁路总公司科技研发计划项目(2013T002-A-2);教育部高等学校学科创新引智计划项目(B13002);中央高校基本科研业务费专项基金项目(2012JBM007)

摘　　要：对Q345B热轧无缝钢管加工的光滑和缺口圆棒试件进行单调加载试验,获取其应力-应变关系、载荷-位移曲线及基本材料参数,研究GTN损伤模型参数取值范围,采用逆推法识别GTN参数,在ABAQUS中利用自编GTN损伤模型UMAT用户子程序实现圆棒试件试验过程的数值模拟,依据数值分析结果比较孔洞的初始体积分数f0、形核孔洞体积分数fn和表征材料失效时的孔洞破坏体积分数fF三个损伤参数对断裂预测结果的影响。结果表明:试件失效点位置随着f0和fn的增大提前出现,而fF越大,试件断裂后下降段斜率则越小,并据此确定Q345B热轧无缝钢管材GTN损伤模型参数,所识别参数可以较准确预测钢试件的断裂点。In this study, smooth and notched round bar coupons extracted from Q345B hot-rolled seamless circular hollow members were tested under monotonic tensile loading to obtain the stress-strain curves, load-displacement curves and basic material parameters. In addition, the reasonable ranges of the GTN micromechanical damage parameters were reviewed. The calibration method of the GTN parameters were studied and performed by comparing the numerical simulation results with the experimental results of notched round bar specimens. All numerical simulations were carried out with the ABAQUS software, and the UMAT subroutine facility was employed for the implementation of the GTN dilational constitutive model. Moreover, the influence of GTN parameters initial void volume fraction f0, nucleating volume fraction f,, as well as final failure void volume fractionfr on fracture prediction resuhs were analyzed. The result shows that the fracture happens earlier with the increase off0 andfn values, fr affects the slope of the descending branch of load-displacement curves. The larger the fF value is, the smaller the slope will be. Based on these parametric analysis results, the GTN damage parameters of Q345B steel are determined by this method and can accurately predict the mechanic behavior of tested steel coupons.

关 键 词：热轧无缝钢管 静力试验 GTN模型 损伤参数 

分 类 号：TU511.37[建筑科学—建筑技术科学]