H形钢梁弯曲滞回性能研究与数值模拟优化

Research and numerical simulation optimization of bending hysteretic performance of H-shaped steel beams

为完善H形钢梁在纯弯曲荷载作用下的滞回性能的研究,对2类截面的H形钢梁增加一个多周滞回加载制度下的拟静力试验。此加载制度下的目标耗能量与此试件等幅升幅加载制度下达到峰值荷载时的总耗能量相等,因此对该试件的破坏模式、累积损伤和耗能规律进行分析,验证了原设想中存在的不影响滞回耗能的阈值低于0.02 rad。同时进行了有限元对比分析,对此试验已有模型进行了精细化处理。有限元分析中利用热塑性方法模拟了试件焊接残余应力的变化过程,从而在模型加载过程中引入残余应力的影响,使试件的初始刚度、翼缘局部屈曲发生的时刻、极限荷载后刚度退化有显著改善。

To improve the research on the hysteretic performance of H-shaped steel beams under pure bending loads,a pseudo static test under multi cycle hysteretic loading system was added to the H-shaped steel beams of class 2 section.The target energy consumption under this loading system is equal to the total energy consumption of the specimen at the peak load under the constant amplitude loading system.Therefore,the failure mode,cumulative damage and energy consumption laws of the specimen were analyzed,and the threshold value that does not affect hysteretic energy consumption in the original idea is verified to be lower than 0.02 rad.At the same time,the finite element comparative analysis was conducted to refine the existing models in this test.The variation process of welding residual stress of the specimen was simulated using thermoplastic method in finite element analysis,thereby the effect of residual stress was introduced to the model loading process,which significantly improves the initial stiffness of the specimen,the time of local buckling of the flange and the stiffness degradation after ultimate load.