地震作用下的钢管再生混凝土柱破坏机理与损伤量化评估

The quantitative damage evaluation of recycled aggregate concrete-filled steel column under earthquake has been an essential problem and hotspot of safe application for structure. Therefore, study on failure mechanism and quantitative damage evaluation for recycled aggregate concrete-filled steel column was proposed. Firstly, the multi-dimensional correlations of hysteretic property, stiffness degradation and energy dissipation were discussed based on former research of mechanism and constitutive relation. Secondly, the cross correlation function of force- displacement-time under seismic force with visual sensing information integrated, were investigated on the basis of force-displacement data by using the image fuzzy edge algorithm. The cross correlation of nonlinear macro and micro damage variation, bulking failure mechanism was analyzed. Thirdly, characteristic of cumulative damage and failure mode were studied, structure damage judgment, location and degree quantification, calculations were carried out through constructing damage recognition factor. Finally, damage factor and index were calculated, hence the seismic performance-based damage model was obtained. According to damage recognition by means of numerical simulation and quasi static test analysis, seismic damage of recycled aggregated concrete-filled steel column was quantitatively analyzed by damage evaluation mode, which provided theoretical reference for the seismic design of recycled aggregate concrete-filled steel column.

钢管再生混凝土柱组合结构震损量化评估是结构安全应用的关键和热点难题，项目提出了对钢管再生混凝土柱破坏机理与损伤量化评估的研究。首先，在柱的力学与本构关系的研究基础上，讨论柱的滞回性能、刚度退化、能量耗散能力的多维相关性。然后，在力位移传感信息基础上，融合视觉传感信息，探索震损进程中的力、位移与时间变量的互相关函数，分析组合结构材料变量与鼓曲、裂纹损伤等非线性宏观损伤变化、变形破坏图像模糊边缘算法、再生混凝土变量微观组织损伤变化、失效机理的互相关性。进一步地，分析损伤累积特点和破坏机理，构造损伤识别因子进行结构损伤判定、定位及程度量化、计算。最后，通过拟合，计算损伤因子和指标，给出结构优化参数，得到基于性能抗震设计的损伤模型。通过数值模拟的柱损伤识别及拟静力试验分析，用损伤评估模型定量分析钢管再生混凝土柱在地震作用下的损伤情况，为钢管再生混凝土柱结构的抗震设计提供理论参考。

钢管再生混凝土柱组合结构震损量化评估是结构安全应用的关键和热点难题，项目提出了对钢管再生混凝土柱破坏机理与损伤量化评估的研究。本项目主要对钢管再生混凝土柱和钢管普通混凝土进行了低周反复加载试验，研究了低周反复循环抗震试验的钢管再生混凝土（RAC）柱的变形特点和失效机理，并绘制了滞回曲线、骨架曲线、应变曲线等，分析了轴压比和再生混凝土强度对其延性、刚度退化和耗能性能等抗震指标的影响。建立了有限元力学模型以分析变形和力学特点，用有限元方法分析了试件的抗震性能，通过有限元模拟建立骨架曲线数据库，提出了恢复力简化模型，与试验数据吻合度良好，为研究结构地震反应和弹塑性时程分析提供计算参考。构建了可视化、非接触式的视觉系统测量变形的系统，用建立的视觉系统试验平台，在室内和室外进行初步目标的测量试验。为了分析变形与破坏形态特点，实时精确测量试件变形，提出了一种无需标记的全场变形视觉测量方法，阐述了视觉系统结构和三维变形测量原理。并基于此方法开发了三维变形的图像处理改进算法与计算程序。通过视觉采集所得三维序列图像，描述了圆钢管RAC柱的承载能力、耗能能力、刚度及退化能力、全场三维变形及破坏形态的抗震性能，并计算了钢管混凝土柱的三维凸曲变形和应变，揭示了钢管混凝土动态变形行为。此外，研究新型组合梁剪力键抗剪性能、波形钢腹板桥梁的疲劳性能和墩顶处的局部应力特性及对其计算公式进行分析。