爆炸作用下钢框架柱简化双自由度计算模型研究

STUDY ON SIMPLIFIED DOUBLE DEGREE OF FREEDOM MODEL FOR STEEL FRAME COLUMN UNDER BLAST LOADING

为简化爆炸作用下钢框架柱的求解过程,将受爆炸作用的钢框架柱简化成刚性杆弹簧连接体系,同时考虑到爆炸作用下钢柱的塑性变形较大、弹性变形很小,因此,忽略其弹性变形而建立钢框架柱的等效刚塑性双自由度模型。运用拉格朗日方程得到该等效刚塑性模型的运动方程,并通过龙格-库塔法在MATLAB中求解其运动方程,最后与有限元的计算结果进行对比,验证等效刚塑性双自由度模型的合理性。结果表明:钢框架柱的等效双自由度模型合理简单,且计算结果可靠,可用于简化钢柱的抗爆求解。

In order to simplify the solving process of steel frame column under blast loading, the steel frame column was simplified to rigid rod-spring system. The steel frame column under blast loading had large plastic deformation but small elastic deformation, therefore, the steel column could be equivalent to rigid-plastic double degree of freedom ignoring elastic deformation. The motion equation of the equivalent rigid plastic double degree of freedom model was obtained according to Lagrange equation. The motion equation could be solved through software MATLAB by using Runge-Kutta method. The rationality of the simplified model was verified through the comparison of the calculation results from finite element method and Runge-Kutta method. The results showed that the equivalent double degree of freedom was reasonable and simple, and the results were reliable. The simplified model could be used in solution of blast-resistance for simplified steel column.