高强钢平端板连接滞回性能模拟方法

Hysteretic Behavior Simulation of High-Strength Steel Flush End-Plate Connection

为了满足高强钢平端板连接的滞回性能精细化分析和简化分析需求,分别基于实体单元和零长度单元进行了模拟方法研究.基于实体单元进行了隐式分析和显式分析模拟.在隐式分析滞回模拟中存在无法收敛问题;在显式分析模型中改进加载步设置规则,采用每个幅值设置单独加载步的方法,解决了同一加载步有多个加载幅值时的误差过大问题.针对零长度单元,提出了修正四折线模型以考虑对于高强钢平端板连接转动能力预测不可忽略的螺栓弯曲变形和梁翼缘转动两个因素;通过卸载刚度损伤指标取值体现高强钢连接和普通钢连接损伤退化规律的差异性并建立了基于Pinching4模型的简化分析模型.同时,平端板连接的数值模拟表明简化分析模型能较好地模拟滞回曲线中的滑移效应和捏拢效应.

In order to meet the requirements of fine and simplified hysteretic behavior simulation analysis of high- strength steel flush end-plate connection, simulation methods based on solid element and zeroLength element were studied. Based on the solid element, implicit analysis and explicit analysis were conducted. The implicit analysis suffered from inability to converge. In the explicit analysis model, the rule of loading step was improved, and for each amplitude an independent loading step is assigned to minimize large discrepancy occurred in a single step with different amplitudes. Aimed at the zeroLength element, a modified quadri-linear line model was proposed. Two factors, i.e. the bending deformation of the bolts and the rotation of the beam flanges, which cannot be neglected for the high-strength steel flush end-plate connection, were considered. The damage indices of the high-strength steel connection and the normal steel connection were different for the unloading stiffness and a simplified model based on the Pinching4 Model was established. The numerical simulation of the flush-end plate connection shows that the simplified analysis model can well simulate the slip effect and the pinching effect in the experimental hysteresis behavior.