考虑地震持时的钢筋混凝土构件损伤性能指标研究

基于9个RC构件在不同变幅历程下的往复加载试验，研究根据刚度损伤指数对不同变幅历程下的损伤过程给出性能划分标准的可能性，并探讨地震持时、峰值位移、配筋量对RC构件损伤发展的影响。研究发现，刚度损伤指数能够对不同变幅历程下的损伤过程给出统一的性能划分标准，提出了对应于5个性能状态（无损、轻度损伤、中度损伤、重度损伤和破坏）的刚度损伤指数区间，并采用PEER数据库中的9个矩形受弯破坏试件对该标准进行了验证；通过将刚度损伤指数与峰值变形指标、Park-Ang损伤指数进行对比，发现刚度损伤指数与峰值变形指标在界定RC构件的轻度损伤时具有较好的一致性，刚度损伤指数与Park-Ang损伤指数在界定RC构件的中、重度损伤时，两者具有较好的一致性；基于算例分析，讨论了刚度损伤指数与配箍率、强震持时、延性系数的相互关系。

Study on performance index of RC members considering effect of seismic duration

Based on the variable amplitude loading tests of nine RC members, the possibility of giving the performance division standard for the damage process under different variable amplitudes according to the stiffness reduction index was studied. The influence of the duration of earthquake, peak displacement, longitudinal ratio and stirrup ratio on the damage of RC members were also discussed. It was found that the stiffness reduction index provided a unified standard of performance division for RC members under different variable amplitudes, and five performance levels (no damage, mild damage, moderate damage, severe damage and destruction) according to the capacity reduction index are proposed. The standard is verified by nine flexural failure specimens of rectangular section in the PEER database; The stiffness reduction index is in accordance with the peak deformation index in defining the light damage of RC members while the stiffness reduction index is in good agreement with the Park-Ang damage index in defining the moderate and severe damage of RC members. Based on the case study, the relationship between the stiffness reduction index and the stirrup ratio, and that between the effective duration and the ductility coefficient are discussed.