【摘要】 为研究高强度钢材Q460C焊缝连接在地震作用下的反应,对11个Q460C焊缝连接试件进行了8种不同加载制度的单调和循环加载试验,分析比较了不同加载制度下的应力-应变关系,研究其本构模型、力学性能、破坏模式、变形和延性特征以及损伤退化特性,并和母材的性能进行了对比。利用Ramberg-Osgood公式对其循环骨架曲线进行了拟合,确定了拟合计算式中的待定参数;通过试验标定了循环荷载作用下本构模型的参数,采用有限元程序ABAQUS利用混合模型对上述循环加载试验进行了较为准确的有限元模拟。研究结果表明:所有加载制度下试件最终均在焊缝和热影响区交界面拉断,这和焊缝连接处的应力集中有关;与母材单调拉伸性质相比,焊缝连接试件延性下降显著,说明焊接过程对钢材有严重影响,应采取措施避免破坏发生在焊缝区域。更多还原

【Abstract】 In order to study the behavior of the weld of high strength structural steel Q460C under earthquake loading,11 welded high strength structural steel Q460C specimens were tested by 8 different monotonic and cyclic loading regimes.The corresponding stress-strain relationships under these different loading regimes were analyzed.The constitutive model,mechanical properties,failure modes,deformation,ductility and the cumulative damage deterioration were also studied and compared with the behavior of the base metal.Based on the test results,the cyclic skeleton curves were fitted by the Ramberg-Osgood model.The key parameters in the formula were determined.Furthermore the key parameters of the stress-strain constitutive model of the weld of high strength structural steel Q460C under cyclic loading were calibrated by the test results and accurately simulated using ABAQUS with the mixed cyclic constitutive model.The results show that all specimens of welded connection fracture at the weld heat affected zone,which may be caused by the stress concentration.Welding process results in undesirable influence on ductility of steel structures.Measures should be taken to avoid failure at welded connections.更多还原