强腐蚀桥梁钢Q345的J-C本构模型及数值模拟  

Tensile Finite Element Simulation of Q345 Bridge Steel with Strong Corrosion Based on J-C Model

作　　者：张浩[1] 乔文靖[1] 杨帆[1] 朱浩云 ZHANG Hao;QIAO Wenjing;YANG Fan;ZHU Haoyun(School of Civil & Architecture Engineering, Xi′an Technological University, Xi′an 710021, China)

机构地区：[1]西安工业大学建筑工程学院,陕西西安710021

出　　处：《郑州大学学报（工学版）》2021年第6期99-104,共6页Journal of Zhengzhou University（Engineering Science）

基　　金：国家自然科学基金资助项目(51778057,51878057);陕西省自然科学基础研究计划项目(2021JM-434,2021JQ-648)。

摘　　要：为了研究桥梁钢Q345在强酸腐蚀下的应力流动变化规律,将18根桥梁钢Q345试件置于质量分数为36%工业盐酸中,分别浸泡0、1、4、12、48、72 h,并通过准静态拉伸试验得到工程应力-应变曲线,利用Origin软件对颈缩前的真实应力-应变曲线进行拟合,获得了基于J-C模型的强腐蚀桥梁钢Q345弹塑性本构关系。在此基础上,建立ABAQUS有限元模型并加入柔性金属损伤演化以模拟钢板的应力流动规律及颈缩破坏,分析不同强酸腐蚀时间对桥梁钢Q345力学性能退化的影响。结果表明:腐蚀率为0.53%、1.22%、2.47%、4.12%、4.98%的桥梁钢Q345弹性模量分别下降了1.26%、2.36%、4.04%、7.01%、10.93%,屈服强度分别下降了0.61%、2.61%、3.56%、5.37%、6.82%,极限强度分别下降了0.42%、2.31%、3.57%、4.58%、6.42%;腐蚀时间超过12 h后,桥梁钢板的力学性能下降速率曲线较为平缓。J-C本构模型能很好地模拟强腐蚀下桥梁钢的应力流动,采用柔性损伤演化能准确地模拟强腐蚀钢材的延性退化行为。In order to study the variation law of stress flow of bridge steel Q345 with strong acid corrosion,18 Q345 bridge steel specimens were immersed in 36%industrial hydrochloric acid for 0,1,4,12,48 and 72 h,respectively.The engineering stress-strain curves were obtained by quasi-static tensile test.The true stress-strain curve before necking was fitted by Origin software,and the elastic-plastic constitutive relation of strong corrosion bridge steel Q345 based on J-C model was obtained.On this basis,ABAQUS finite element model was established and the damage evolution of flexible metal was added to simulate the stress flow law and necking failure of steel plate,and the influence of different strong acid corrosion time on the mechanical property degradation of bridge steel Q345 was analyzed.The results showed that the elastic modulus of bridge steel Q345 with corrosion rate of 0.53%,1.22%,2.47%,4.12%and 4.98%decreased by 1.26%,2.36%,4.04%,7.01%and 10.93%,respectively,and the yield strength decreased by 0.61%,2.61%,3.56%,5.37%and 6.82%,respectively,the ultimate strength decreased by 0.42%,2.31%,3.57%,4.58%and 6.42%,respectively.The results showed that the decline rate of mechanical properties of bridge steel plate was relatively slow when corrosion time exceeded 12 h.J-C constitutive model could well simulate the stress flow of bridge steel under strong corrosion.The ductile degradation behavior of strongly corroded steel could be accurately simulated by the flexible damage evolution.

关 键 词：强腐蚀 桥梁钢Q345 J-C本构模型 有限元模拟 柔性损伤 

分 类 号：U444[建筑科学—桥梁与隧道工程]