Twin-PBL剪力键疲劳性能试验及有限元分析

Fatigue Performance Test and Finite Element Analysis for Twin-PBL Shear Connectors

为研究Twin-PBL剪力键在循环荷载作用下的力学性能,进行了5个Twin-PBL剪力键的疲劳推出试验。分析了其在不同疲劳荷载幅下的疲劳破坏模式、疲劳性能及荷载-滑移曲线。结合有限元仿真软件MIDAS/Fea进行空间实体建模,将有限元计算结果与推出试验得出的数据和构件损伤形式进行了对比分析,并拟合得到平均相对误差为9. 09%的荷载与寿命曲线方程。结果表明:在疲劳试验中,Twin-PBL剪力键的疲劳损伤寿命随疲劳荷载幅的增大而趋于短折; Twin-PBL剪力键疲劳试验后的残余滑移量能表征疲劳损伤的程度;有限元仿真模拟与疲劳试验相互印证了Twin-PBL剪力连接件的破坏模式,即混凝土板自底部呈45°斜向劈裂,开孔处混凝土榫剪碎,贯穿钢筋剪切变形。

In order to research the fatigue performance of Twin-PBL shear connector under cyclic loading,five Twin-PBL shear connector specimens were made and experimented in push-out test.The failure mode,the fatigue performance and the load-slip curves of the specimens were analyzed in this paper.The spatial solid model was built by finite element simulation software MIDAS/Fea,the results and fatigue failure ways of finite element analysis had been analyzed and compared with the push-out test,and the load and life curve equation with the average relative error of 9.9%were fitted and obtained.The results show that in the fatigue load push-out test,the fatigue life of Twin-PBL shear connector tends to be shorter as the fatigue load amplitude increases.The amount of residual slippage after the fatigue test of Twin-PBL shear connector can characterize the degree of fatigue damage.The finite element simulation and fatigue tests conf irmed the failure mode of the Twin-PBL shear connectors that the concrete slab splits obliquely at 45°from the bottom,and the concrete dowels of the specimens on the hole was cut and the shear deformation of the steel bar occurred.