低周反复荷载下两跨两层轻钢框架抗震性能试验研究

本文通过两跨两层轻钢框架试件的低周反复加载试验,研究了轻钢框架结构在地震作用下的滞回性能、耗能机制、耗能能力、刚度退化和破坏形态,结果显示轻钢框架具有很好的抗震性能,节点域耗能能力强。论文结论可为多层轻钢框架的抗震设计提供依据。     

梁端楔形翼缘连接钢框架抗震性能和抗震设计研究

根据两跨两层梁端楔形翼缘连接钢框架试件的低周反复加载试验,研究了梁端楔形翼缘连接钢框架结构在地震作用下的滞回性能、耗能机制、耗能能力和破坏形态。结果显示,试件破坏模式为延性,塑性铰出现在梁翼缘变化处,远离梁柱交界,梁端楔形翼缘连接钢框架具有良好的抗震性能。针对梁端楔形翼缘连接钢框架的特点,提出了强柱弱梁、强节点弱杆件和节点域抗震设计要求。     

Test and evaluation of modified TADAS devices with different grades of steel

Triangular-plate added damping and stiffness(TADAS) devices are reliable metallic energy dissipaters for seismic upgrading used in design and retrofitting of civil structures. Conventional TADAS devices are designed with closedended slots. In this study, a modified form of the TADAS device is proposed with open-ended slots in order to reduce the manufacture cost, facilitate the assembling and avoid abrupt stiffness increase. Cyclic and monotonic loading tests are then conducted to investigate the mechanical characteristics of the modified TADAS devices with regular Q345 steel and lowyield point LY160 steel triangular plates. The test results show that although the hysteresis performances are stable, the cyclic hardening behavior is different between the TADAS specimens with different grades of steel. The TADAS specimen with LY160 triangular plates exhibits more significant overstrength behavior than the one with Q345 triangular plates in cyclic loading, which is unsuitable to be described by the classic Bouc-Wen model. Therefore, a modified Bouc-Wen model is proposed to describe such overstrength behavior. It is shown that the modified model is able to simulate different extent of overstrength behavior in cyclic loading, based on which the cyclic hardening behavior of the TADAS specimen with LY160 triangular plates can be well described.