低周交变荷载下新型盲孔螺栓端板连接钢管砼柱节点的损伤机理及抗震性能研究

It is the purpose of this study to further the understanding of low cycle repeated loading induced damage accumulation effects and evolution manners of an innovative blind bolted endplate connection to concrete filled tubular columns. Through experimental testing and numerical modelling, the joint components, local and global models are investigated in terms of low cycle fatigue mechanism & mechanical properties, and low cycle fatigue failure analytical and evaluation methods. This research project includes: (1) low cycle fatigue behaviour and micro damage characteristics of blind bolts, referring to mechanical damage properties and material failure mechanisms; (2) damage accumulation mechanism of joint local models, referring to multiple influential factors induced failure mechanisms, damage evolution manners and energy dissipation mechanisms. These models relate to blind bolted endplate connections in tension zone, blind bolted connections to concrete filled tubular columns and combined actions of blind bolted connection and anchorage; (3) damage assessment and fatigue life prediction of joint overall models, referring to energy dissipation mechanisms, failure modes, damage accumulation rules and low cycle fatigue life prediction methods of joint overall models deriving from aforementioned joint component and local models; (4) safe evaluation methods and improved configuration advice for these joints under low cycle fatigue. Finally, as a conclusion of this study, an improved understanding for codification, better joint configuration and seismic optimisation will be presented for this innovative blind bolted endplate connections to concrete filled tubular columns as key scientific basis and technical backup.

本项目以低周交变荷载作用下新型盲孔螺栓端板连接钢管砼柱节点的损伤累积效应及其演化规律为主线，通过试验和数值模拟，系统性研究节点的低周疲劳损伤机理及力学特性，低周疲劳失效分析和工程评估方法，包括：(1)盲孔螺栓的低周疲劳行为、细观疲劳损伤特性，研究盲孔螺栓的力学破坏特征和材料损伤失效机理；(2)节点局部模型的损伤积累破坏机理分析，研究多因素影响下受拉区盲孔螺栓与端板连接、盲孔螺栓连接与钢管混凝土柱组合、以及盲孔螺栓连接与锚固组合的失效机理、损伤演化规律和能量耗散机制；(3)节点整体模型的损伤评价及疲劳寿命预测，研究基于节点组件和局部模型的能量耗散机制、失效模式、积累损伤破坏准则及低周疲劳寿命预测方法；(4)节点低周疲劳失效的工程评估方法与抗震对策。通过研究，为推进新型盲孔螺栓端板连接钢管砼柱节点的抗震设计规范化、构造措施改进和抗震性能优化提供科学依据和关键技术支持。

本项目以低周疲劳荷载作用下钢管混凝土柱-锚固式盲孔螺栓端板连接节点的损伤累积效应及其演化规律为主线，通过试验和数值模拟，系统性研究节点的低周疲劳损伤机理及力学特性，低周疲劳失效分析和工程评估方法，包括：(1)盲孔螺栓的低周疲劳行为、细观疲劳损伤特性，研究盲孔螺栓的力学破坏特征和材料损伤失效机理；(2)节点局部模型的损伤积累破坏机理分析，研究多因素影响下受拉区盲孔螺栓与端板连接、盲孔螺栓连接与钢管混凝土柱组合、以及盲孔螺栓连接与锚固组合的失效机理、损伤演化规律和能量耗散机制；(3)节点整体模型的损伤评价及疲劳寿命预测，研究基于节点组件和局部模型的能量耗散机制、失效模式、积累损伤破坏准则及低周疲劳寿命预测方法；(4)节点低周疲劳失效的工程评估方法与抗震对策。通过研究，为推进钢管混凝土柱-锚固式盲孔螺栓端板连接节点的抗震设计规范化、构造措施改进和抗震性能优化提供科学依据和关键技术支持。