基于板梁理论的工字形钢—混组合双跨连续梁弯扭屈曲分析

Flexural-torsional buckling analysis on I-shaped steel-concrete composite double-span continuous beams based on plate-beam theory

基于板梁理论,对均布荷载作用下的双轴对称工字形钢—混组合双跨连续梁进行弯扭屈曲分析,推导截面连续梁发生弯扭屈曲时的临界弯矩公式,运用ANSYS有限元软件对10根双轴对称工字形钢—混组合双跨连续梁进行特征值屈曲分析,对比屈曲临界弯矩的数值解与理论解,讨论换算截面法的适用性。结果表明:理论解与有限元解之间具有较高的吻合度,最大误差不超过3%。换算截面法的计算结果与实际结果差别较大,并不适用于工字形钢—混组合连续梁弯扭屈曲问题的计算。

Based on the plate-beam theory,the analysis of the flexural-torsional buckling(LTB)of the doubly symmetric I-shaped steel-concrete composite double-span continuous beams subjected to uniform load is made,and the formula for the critical buckling moment of the beams is deduced.The eigenvalue buckling analysis of ten doubly symmetric I-shaped steel-concrete composite continuous beams is carried out by using ANSYS software,and the numerical solutions and theoretical ones of critical buckling moment are compared,the applicability of the transformed section method is discussed.The results show that there is a good agreement between the theoretical solutions and those of finite element analysis,and the maximum relative error is less than 3%.The calculation results of the transformed section method are different from the actual ones and it is not applicable to the calculation of flexural-torsional buckling problems of I-shaped steel-concrete composite double-span continuous beams.