基于性能提升的螺栓-组件连接抗倒塌分析

框架竖向承重构件失效后,节点的性能决定了荷载是否能可靠地传递给相邻构件。栓焊刚性连接具有较高的初始刚度,在大变形条件下梁端母材易过早断裂,悬链线机制的发挥无法保证;顶底角钢腹板双角钢半刚性连接虽然具有较大变形能力,但在早期小变形阶段承载力偏低,性能有所不足。为全面提高节点的抗倒塌性能,设计了1种螺栓-组件连接节点,通过建立理论模型与数值模型进行相互验证,对该连接方式的抗倒塌性能进行了细致分析。结果表明:螺栓-组件连接子结构初始阶段承载力高于栓焊连接,并且在过渡阶段稳定上升,具有较大的转动变形能力。通过将梁腹板局部加厚,可使其在大变形条件下的承载力高于双腹板顶底角钢半刚性连接,抗倒塌性能优越。该新型连接节点传力明确,各组件工作性能合理高效,理论分析表明组件约束长度β、壁厚h和滑道长度d是影响其抗倒塌性能的关键因素,并给出了设计建议。

Analysis of anti-collapse performance of bolt-component connection based on performance improvement

After the failure of the vertical load-bearing members of the frame, the performance of the connection determines whether the loads can be reliably transmitted to adjacent members. The bolt-weld mixed rigid joint has a high initial stiffness, but the base material of the beam end is easy to fracture prematurely under large deformation, and the catenary mechanism can not be guaranteed. The semi-rigid connection with angles at the top and bottom flanges and two sides of the web has a large deformation capacity, but its bearing capacity is low in the early stage of small deformation and the performance is insufficient. In order to comprehensively improve the anti-collapse performance of the joints, a bolt-assembly connection was designed in this study. The theoretical model and numerical model were used to verify each other, and the collapse resistance of the proposed connection was analyzed in detail. The results show that at the initial stage, the bearing capacity of the bolt-component joint is higher than that of the bolted joint, and it rises steadily during the transition period and present a large deformation capacity. By thickening the beam web locally, the bearing capacity of the proposed connection under the large deformation conditions is higher than that of the semi-rigid connection with angles at the top and bottom flanges and two sides of the web, and the anti-collapse performance is superior. The new connection has clear force transfer mechanism and the working performance of each component is reasonable and efficient. The theoretical analysis shows that the component constraint length β, wall thickness h and slide length d are the key factors affecting the collapse resistance performance. In the end, the design suggestions are given.