基于混凝土受压损伤信息的RC柱地震损伤量化研究

Quantitative evaluation of earthquake damage for RC column based on concrete compression damage information

材料的微观损伤反映了结构损伤的内在本质,建立由材料损伤表达的构件地震损伤模型是基于性能抗震设计的重要基础。为实现从材料损伤到构件整体损伤的过渡,建立了由剪跨比和轴压比表达的钢筋混凝土柱(RC柱)失效模式判别准则,以混凝土的受压损伤信息表征RC柱的材料损伤,计算典型损伤区域的混凝土受压损伤因子最大平均值作为损伤指标。通过柱在低周往复荷载作用下形成的具有明确物理意义的骨架曲线,确定构件性能临界点和相应的混凝土材料受压损伤阶段,由此建立基于材料损伤的构件地震失效模型。以弯曲失效为例,经多组构件统计分析,由混凝土受压损伤信息建立RC柱性能阶段判别标准,从本质上反映了RC柱失效演化过程中内在损伤发展规律,实现了RC柱的地震损伤量化。

The micro damage of materials reflects the intrinsic nature of structural damage.It is important for performance-based seismic design to establish the seismic damage model of components expressed by material damages.To realize transition from material damage to component damage, a failure mode criterion expressed by shear span ratio and axial compression ratio of Reinforced Concrete column(RC column) is established.The material damage of RC column is characterized by compression damage information of concrete, and the maximum average value of concrete damage factor in the typical damage area is calculated as the component damage index.According to the skeleton curve formed by the column under low cyclic loading, the critical point of component performance and the corresponding deterioration stage of concrete material are determined, and the seismic failure model of the component based on material damage is established.Taking bending failure as an example, the criterion of RC column performance stage based on concrete compression damage information is established through the statistical analysis of multiple groups of members, which essentially reflected the inherent damage development law in the failure evolution process of RC column, and realized the seismic damage quantitative evaluation of RC column.