强震作用下钢材等效本构模型应用研究

为研究考虑损伤退化的钢材等效本构模型在整体框架中的应用及其用于强震作用下钢框架结构弹塑性时程分析的可行性，选取已有典型钢框架静力及动力试验，对其分别采用等效本构模型和传统的两折线模型进行计算，并与试验结果进行对比分析，验证等效本构模型的可靠性和对计算精度的提高作用。在此基础上，将等效本构模型应用于10层钢框架结构抗震性能分析中，采用增量动力分析法，研究损伤累积退化对多高层钢框架结构强震作用下动力响应的影响，并与不考虑损伤退化的模型计算结果进行对比分析。分析结果表明：累积损伤退化的发生会加剧结构的动力响应，若不考虑此影响，会低估结构变形，导致结构存在一定的安全隐患。采用等效本构模型的增量动力分析能够较为合理地反映结构在强震作用下的承载性能退化现象，但不同地震波作用下的计算结果差异较大。

Application study on equivalent constitutive model of steel subjected to strong earthquake

In order to verify the applicability of steel equivalent constitutive model considering damage and degradation in steel frame, typical tests of both static and dynamic loadings were adopted. The applicability of the model in time history analysis for steel frames was proved. The test results were compared with proposed model and traditional model to prove the reliability of proposed model and the enhancing effect on calculation accuracy. Base on the verification, the model was applied in seismic analysis of a ten-story steel frame and compared with the cyclic constitutive model without considering damage and degradation. Incremental dynamic analysis was performed to study the effect of damage and degradation on dynamic behaviours of steel frame subjected to strong earthquakes. The analysis results show that: the cumulative damage would aggravate the dynamic response of steel frame under strong earthquake. If this factor is not be considered, the deformation capacity would be underestimated, leading to unsafe design. Incremental dynamic curves with proposed model could reasonably reflect capacity degradation under earthquake. However, the calculative results of different earthquake waves are quite different.