爆炸荷载作用下钢管混凝土柱非线性分析

Nonlinear Analysis of Concrete-filled Steel Tubular Columns Under Blast Load

基于统一强度理论,推导了钢管混凝土柱的塑性极限弯矩和均布荷载作用下简支梁的极限位移。考虑爆炸反应过程中钢管混凝土柱质量和刚度改变产生的非线性影响,采用等效单自由度模型和逐步积分法,分析了爆炸荷载作用下钢管混凝土柱的动态响应。将理论计算结果与相关文献计算结果进行对比,验证了理论计算方法的正确性。研究结果表明：随着套箍系数的增大,塑性极限弯矩及极限位移增大;随着侧压系数的增大,塑性极限弯矩增大;考虑钢管对受压区混凝土抗压强度的提高比不考虑时塑性极限弯矩提高了12%-19%;提出的计算方法满足钢管混凝土柱抗爆分析的精度要求,可为钢管混凝土柱的抗爆设计和防护提供参考。

The plastic ultimate moment of concrete‐filled steel tubular and the ultimate displacement of the simply supported beam under uniformly distributed load were derived based on unified strength theory .Considering nonlinear impact of mass and stiffness changed in the process of the reaction ,the dynamic responses of concrete‐filled steel tubular columns under blast load were analyzed by the equivalent single degree of freedom model and step by step integration method .The results of this method were compared with relevant literatures and the accuracy of the method was verified . The study results show that the plastic ultimate moment and the ultimate displacement increase along with the increase of hoop coefficient ;the plastic ultimate moment also increases along with the increase of lateral pressure coefficient ;the plastic ultimate moment considering the improvement of the compressive strength of concrete increases 12%‐19%than that without considering the improvement . The proposed method is satisfied for the requirement of the analytical precision ,and can be referred for the research and the safety of concrete‐filled steel tubular columns under blast load .