性能参数对混凝土柱破坏指数的影响

Influence of Performance Parameters on Damage Index of Concrete Columns

不同破坏准则对混凝土柱的破坏程度评价结果存在一定差异。针对已有抗震研究多考虑最终破坏指数与构件破坏程度的对应关系,未考虑不同破坏准则与构件性能参数选取对评估结果合理性的影响。以混凝土柱为研究对象,计算了极限状态下位移角与位移角限值比值、承载力与峰值承载力比值、变形与变形能力比值与双参数准则、延性准则破坏指数之间的相关系数,分析了破坏指数与破坏现象、破坏规律的吻合程度,探讨了几种性能参数对不同破坏准则的适用性。结果表明:极限状态下混凝土柱的变形能力值离散性最小,与位移角比值、承载能力退化值的相关性最低,更适合应用于破坏准则研究;双参数破坏准则计算结果受组合系数β的取值影响显著,反映的混凝土柱破坏趋势与承载力变化规律、试验现象存在较大差异;由延性破坏准则计算得出的破坏指数能反映位移角比值、承载力退化值、变形能力值对破坏的影响规律,考虑变形能力极限的延性准则能更好地量化混凝土柱的破坏。

The evaluation results of damage degree of concrete columns using different damage criteria are usually different.The existing seismic research mainly focuses on the corresponding relationship between the final failure index and the failure degree of members,whereas the influence of different failure criteria and the selection of member performance parameters on the rationality of the evaluation results is not considered.Taking the concrete column as the research object,the correlation coefficients between the ratio of displacement angle to the limit value of displacement angle,the ratio of bearing capacity to peak bearing capacity,and the ratio of deformation to deformation capacity and the failure index of double parameter criterion and ductility criterion were calculated.The coincidence degree of failure index with failure phenomenon and failure law was analyzed,and the applicability of several performance parameters to different failure criteria was discussed.The results show that the discreteness of deformation capacity value of concrete column in limit state is the smallest,and the correlation with displacement angle ratio and bearing capacity degradation value is the lowest,which is more suitable for the study of failure criterion.The value of combination coefficientβhas a significant impact on the calculation results of double parameter failure criterion.There are great differences among the failure trend of concrete columns,the variation law of bearing capacity and test phenomena.The failure index calculated by the ductile failure criterion can reflect the influence law of displacement angle ratio,bearing capacity degradation value and deformation capacity value on failure.The ductility criterion considering the limit of deformation capacity can better quantify the failure of concrete columns.