整体锈蚀与剪跨段锈蚀高性能钢梁失效行为对比  

Comparation of failure behavior of high-performance steel beams with general corrosion and shear-span corrosion

作　　者：肖林发 彭建新 陈华鹏 XIAO Lin-fa;PENG Jian-xin;CHEN Hua-peng(School of Transportation Engineering,East China Jiaotong University,Nanchang 330013,Jiangxi,China;School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,Hunan,China)

机构地区：[1]华东交通大学交通运输工程学院,江西南昌330013 [2]长沙理工大学土木工程学院,湖南长沙410114

出　　处：《长安大学学报（自然科学版）》2023年第6期71-82,共12页Journal of Chang’an University(Natural Science Edition)

基　　金：国家重点研发计划项目(2022YFB2602200,2021YFE0105600);国家自然科学基金项目(52208168);江西省自然科学基金项目(305185776028)。

摘　　要：为探究整体锈蚀与剪跨段锈蚀高性能钢梁的失效机理差异,设计9片H形Q460D高性能钢梁,对比研究整体锈蚀与局部锈蚀高性能钢梁的抗弯力学性能。首先,通过电化学加速锈蚀方法得到不同锈蚀水平的上述2类锈蚀钢梁,基于3D扫描技术重现锈蚀钢梁的空间形态。接着,开展了钢梁的四点弯曲加载试验,讨论2种钢梁的截面离散性、各部件的长细比以明确锈蚀对几何特性的影响,对比分析荷载-变形响应、腹板与翼缘的应变发展规律以及失效行为。最后,考虑材料力学性能退化和几何初始缺陷等因素,基于ANSYS软件建立有限元模型,详细探究锈蚀长度以及锈蚀水平等因素对钢梁退化性能的影响。结果表明:锈蚀会降低截面的离散性,并促使受压翼缘均变为纤细型;锈蚀程度低于临界锈蚀水平10%时,2组梁强度和刚度退化不大;进一步锈蚀时,会导致整体锈蚀梁提前发生侧向扭转变形和局部屈曲,剪跨段局部锈蚀梁则由局部屈曲失效转变为腹板屈曲失效;数值分析发现受压翼缘或者受拉翼缘的锈损对于整体锈蚀试验梁的力学行为影响较小,加劲肋与腹板对钢梁的抗弯性能影响较大;锈损大于30%后,剪跨段锈蚀梁的力学性能退化明显,锈蚀长度进入到近跨中侧的腹板中部附近时,失效位置将会由跨中逐渐转移到剪跨段的锈蚀分界面上。In order to explore the difference in the failure mechanism of the general corrosion and shear-span corrosion high-performance steel(HPS)beams,9 H-shaped Q460D high-performance steel beams were designed,and the bending mechanical properties of these two kinds of beams were compared and studied.Firstly,the two types of corroded steel beams with different corrosion levels were obtained by electrochemical accelerated corrosion method.Based on 3D scanning technology,the spatial morphology of corroded steel beams were reproduced.Then,the four-point bending loading tests of steel beam were carried out.The section discreteness of two kinds of steel beams and the slenderness ratio of each component were discussed to clarify the influence of corrosion on geometric characteristics.The load-deformation response,strain development law of web and flange and failure behavior were compared and analyzed.Finally,considering the degradation of material mechanical properties and geometric initial defects,finite element models were established based on ANSYS software.The influence of factors such as corrosion length and corrosion level on the degradation performance of steel beams was explored in detail.The results show that corrosion reduces the dispersion of the cross-section area,and promotes the compression flange to become slender.When the corrosion damage is less than the critical corrosion level 10%,the strength and stiffness of the two groups of beams are not degraded much.Further corrosion causes the general corroded beam to undergo lateral torsional deformation and local buckling in advance,and the failure model of the local corroded beam in the shear span changes from local buckling failure to web buckling failure.In addition,numerical analysis found that the corrosion damage of the compression flange or the tension flange has little effect on the mechanical behavior of the general corroded test beam,and webs and stiffeners have greater influence on the bending performance.When the corrosion damage is higher than 30%,the

关 键 词：桥梁工程 高性能钢 数值模拟 锈蚀 抗弯性能 失效机理 

分 类 号：U448.225[建筑科学—桥梁与隧道工程]