多轴加载条件下结构钢基材及焊接件低周疲劳性能试验研究

发布时间：2017-12-28 13:30

本文关键词：多轴加载条件下结构钢基材及焊接件低周疲劳性能试验研究　出处：《建筑结构学报》2016年12期 　论文类型：期刊论文

【摘要】：焊接钢结构的局部往往处于复杂的多轴非比例受力状态,在动力循环荷载作用下钢结构的局部失效破坏主要为多轴非比例疲劳所致。采用薄壁圆管试件进行了多轴加载条件下Q235B钢基材和焊接件的低周疲劳性能试验,对比了基材和焊接件的基本力学性能和低周疲劳性能;采用KBM和FS临界面准则进行了Q235B钢基材和焊接件的低周疲劳寿命预测。研究结果表明:多轴非比例加载路径下,Q235B钢基材及焊接件都存在明显的循环附加强化效应,导致其相对于单轴或多轴比例加载路径下的疲劳寿命更低;KBM准则能较好地预测多轴比例加载路径下的疲劳寿命,而对多轴非比例加载路径下的疲劳寿命的预测偏于不安全;FS准则通过考虑材料的非比例强化效应对多轴疲劳附加损伤的影响,能显著提高对多轴非比例加载路径下的疲劳寿命的预测精度。
[Abstract]:The part of welded steel structure is often in a complex multi axial non proportional stress state. Under dynamic cyclic loading, the local failure of steel structure is mainly caused by multi axial non proportional fatigue. The thin-walled tube specimens under multiaxial loading conditions of low cycle fatigue properties of Q235B steel base material and welding parts, welding parts of the substrate and compares the basic mechanical properties and low cycle fatigue performance; using KBM and FS Pro interface criterion for prediction of low cycle fatigue life of Q235B steel base material and welding. The research results show that the multi axial non proportional loading path, Q235B steel base material and welding parts have obvious cyclic additional hardening effect, resulting in lower fatigue life compared with single or multi axis under proportional loading path; KBM criterion can multi axis fatigue life prediction under proportional loading path is better, and the fatigue life prediction the multi axial non proportional loading path of the unsafe; FS criterion by considering the material non proportional multiaxial fatigue effect on strengthening effect of additional damage, can significantly improve the prediction precision of multi axial non proportional loading paths.
【作者单位】：武汉理工大学道路桥梁与结构工程湖北省重点实验室;
【基金】：国家自然科学基金重点项目(51438002),国家自然科学基金面上项目(51378409)
【分类号】：TG406;TU511.3
【正文快照】： 0弓|| 在循环荷载作用下钢结构的失效大多是由疲劳破坏所致。如高耸钢结构的风振疲劳、地震作用下多高层钢框架梁柱焊接节点的低周或超低周疲劳,以及重型工业厂房中钢吊车梁和节点的疲劳问题等'同时,由于实际焊接钢结构杆件连接的几何特征和受力形式复杂,节点区通常处于多轴

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