锈蚀钢结构地震损伤行为与抗震性能评定方法

Steel structure engineering is often difficult to avoid the corrosion by protection and construction measures, which is used in large industrial buildings and marine engineering. Uneven corrosion pit on steel structure surface will not only reduce steel plastic deformation and fracture toughness, but also accelerate the crack propagation. It will affecte steel structure performance during follow-up period. This project is based on the existing steel structure seismic performance degradation. The experimental research and theoretical analysis combined with numerical simulation will be used. The key scientific problems will be studied on earthquake damage behavior and seismic performance evaluation of the corrosion steel structure. Based on the studies of damage accumulation mechanism under low cyclic loading, a damage cumulation model will be proposed for steel or weld seam. A cyclic plastic constitutive model will also be presented for steel. The hysteretic performance degradation row will be studied for steel members or joint under low cyclic loading. A restoring force model for corroded steel member or joint under low cyclic loading will be proposed. The determination method for corrosion steel member of plastic hinge characteristics parameter will be proposed. The law of plastic hinge formation and distribution will be analyzed. The mechanism of earthquake disaster for corrosion steel structure will be revealed. The earthquake failure criterion of corroded steel structure will be established and the seismic performance evaluation method will be proposed. It will further improve the theory to evaluate seismic performance of existing steel structure. It will provide the technical basis for the civil engineering disaster prevention and reduction.

长期处于工业、海洋大气等腐蚀环境下的钢结构工程，往往难以通过防护和构造措施避免锈蚀，而钢结构表面锈坑则降低了钢材塑性和断裂韧性，加快了裂纹扩展，这无疑对钢结构工程后续服役期抗震性能产生较大影响。本项目以腐蚀环境下既有钢结构抗震性能退化为工程背景，采用试验研究、理论分析与数值模拟相结合的方法，围绕"锈蚀钢结构地震损伤行为与抗震性能评定方法"展开系统研究。通过低周往复荷载作用下锈蚀钢材（焊缝）损伤累积机理研究，建立锈蚀钢材（焊缝）损伤累积模型，提出锈蚀钢材循环塑性本构模型；研究低周往复荷载作用下锈蚀钢构件（节点）滞回性能退化规律，建立锈蚀钢构件（节点）恢复力模型；提出锈蚀钢构件塑性铰特征参数确定方法，分析其塑性铰形成与分布规律，揭示锈蚀钢结构地震灾变机理；建立锈蚀钢结构地震破坏准则，提出其抗震性能评定方法。研究成果将进一步完善既有钢结构抗震性能评估理论，为我国土木工程防灾减灾提供技术依据。

长期处于腐蚀环境下的钢结构工程，往往难以通过防护和构造措施避免锈蚀，引起材料、构件、结构动力行为和地震灾变机理发生改变，造成抗震性能退化。该项目以腐蚀环境下既有钢结构抗震性能退化为工程背景，致力于解决锈蚀钢结构地震损伤行为与抗震性能评定方法涉及的关键科学问题，围绕锈蚀损伤后材料、构件和结构的非线性动力行为等问题进行了系统的试验研究和理论分析，通过锈蚀钢材（焊缝）低周往复荷载试验，研究了锈蚀钢材（焊缝）的损伤累积机理，提出了锈蚀钢材（焊缝）循环塑性本构模型；通过开展锈蚀钢构件（节点）低周往复荷载试验，研究了锈蚀钢构件（节点）抗震性能退化规律，建立了锈蚀钢构件（节点） 恢复力模型，提出了锈蚀钢构件塑性铰特征参数确定方法，通过分析塑性铰形成与分布规律，揭示了锈蚀钢结构地震灾变机理，建立了锈蚀钢结构地震破坏准则与抗震性能评定方法。研究成果将进一步完善既有钢结构抗震性能评估理论，为我国土木工程防灾减灾提供技术依据。