爆炸作用下钢筋混凝土柱非线性动力响应及破坏模式分析方法

Analytical approach of nonlinear dynamic responses and failure modes of RC columns under blast loads

为建立爆炸作用下钢筋混凝土柱非线性动力响应及破坏模式的高效分析方法,从材料应力-应变关系出发,分别应用截面分层法、修正压场理论方法(MCFT)和Krauthammer模型建立了单调加载条件下抗力曲线(包括截面弯矩-曲率关系、平均剪应力-平均剪应变关系和直剪剪力-直剪滑移关系),并以单调加载条件下抗力曲线为骨架,提出了加卸载条件下RC柱截面抗力曲线;在此基础上,根据Timoshenko梁理论和有限差分方法,建立了爆炸作用下RC柱非线性动力响应的显式分析方法。研究结果表明:本文方法能够定量分析爆炸作用下RC柱的动力响应和破坏模式,计算结果与相关试验数据有较好的一致性。

In order to establish an efficient approach to analyze the non-linear response and to predict failure modes of RC columns under blast loading,the cross-sectional resistance functions,including the relationships of cross-sectional moment versus curvature,average shear stress versus average shear strain and direct shear stress versus direct shear slip under monotonic loading were firstly established by the layer model,the MCFT model,and Krauthammer＇s model,respectively.New hysteretic models for the resistance functions under cyclic loading conditions were then proposed.The governing equations of blast-loaded RC columns,which were derived from the Timoshenko＇s beam theory,were discretized by the finite difference method.Finally,an explicit analytical approach for the prediction of the non-linear responses and failure modes of RC columns subjected to blast loading was proposed.The results reveal that the approach can predict the responses and failure modes of RC columns quantitatively,which is validated by the good agreement between the numerical results and the test data.