梁端加强板构造对可更换耗能梁段受力性能的影响

为了改善可更换结构体系中可更换耗能构件的受力性能，提出一种梁端端板螺栓+加强板连接构造的可更换耗能梁构件。设计并制作了2个足尺的剪切屈服型可更换耗能梁试件，对其进行拟静力反复加载试验，并采用ABAQUS软件进行有限元模拟分析，探讨梁端连接构造对可更换耗能梁破坏模式、承载力、梁端塑性应变等特征的影响。试验结果表明：试件的破坏模式为腹板-加劲肋焊缝断裂或翼缘-端板焊缝断裂，试件具有良好的承载力和耗能能力；梁端加强板构造能有效转移梁端翼缘-端板焊缝区域的塑性应变，避免构件提前发生翼缘-端板焊缝断裂，导致无法满足其变形和震后可更换需求；有限元模拟结果与试验结果吻合较好，验证了有限元模型的有效性。对5类梁端加强板构造模型进行非线性分析，结果表明，该类梁端构造均能改善梁端翼缘-端板焊缝区域应力集中现象，优化其受力特征。提出可更换耗能梁梁端端板螺栓+加强板构造的设计方法，并通过有限元模型验证了其可行性。

Mechanical performance of the replaceable like with different end web stiffeners

In order to improve the mechanical property of the replaceable links in structural system with replaceable members, a novel type of the replaceable link with bolted end plate connection and end web stiffeners was proposed. The quasi-static test on two full-scale replaceable links was carried out and the finite element simulation analysis of the models was conducted using ABAQUS software to evaluate the influence of the stiffener configurations at the end of link flanges on the failure mode, bearing capacity, flange plastic strain. The test results show that all specimens yielded in shear, followed by two types of failure modes, i. e., web-to-stiffener weld tear and fracture at the flange-to-end plate welds, those of which showed a stable bearing strength and excellent energy dissipation behavior. Meanwhile, the specimen with end web stiffeners was effective in shifting plastic flange strains away from the flange-to-end plate welds to sustain ductile inelastic deformation and replaceability under cyclic loading. The finite element simulation results were in good agreement with the experimental results, which verified the validity of the finite element model. Feartures of the plastic strains of these modes indicated that five end stiffener configurations shifted flange plastic strains caused by link deformation away from the welds to strength the seismic performance. Finally, the proposed formula for the replaceable link with bolted end plate connection and end web stiffeners was recommended, and the feasibility of design method was verified.