刚性基底弹性转动约束矩形板各受载条件下屈曲分析

Explicit Buckling Analysis of Rotationally Restrained Plates on Rigid Base Under Various Loading Conditions

为探究对于刚性基底上边界不同弹性转动约束刚度矩形板的单侧屈曲行为,研究了在刚性基底上弹性转动约束矩形薄板四边受线性压力和均布剪力屈曲的问题.采用Rayleigh-Ritz法,依据不同受载情况的屈曲形变提出合适的挠曲面函数,由板屈曲时能量的变分推得临界屈曲荷载理论解.运用相关性稳定验算公式,获得薄板在弯-剪复合应力下的屈曲公式.建立相关有限元模型,分析不同基底刚度和弯剪比对弯-剪复合屈曲应力的影响,并与一个半充填式钢箱-混凝土组合梁负弯矩区腹板屈曲试验结果比较.结果表明:半充填混凝土作刚性基底时可简化为刚度系数略低于5的弹性基底.

In order to investigate the unilateral buckling behavior of rectangular plates with different elastic rotational restraint stiffnesses on the rigid foundation,the buckling of rectangular plates with elastic rotation constraints on the rigid foundation under linear pressure and uniform shear force is studied.According to the buckling deformation under different loading conditions,the appropriate deflection surface function is proposed,and the theoretical solution to critical buckling load is deduced from the energy variation of plate buckling by using the Rayleigh-Ritz method.The buckling formula of the thin plate at the combined bending-shear stress is obtained by using the correlation stability checking formula.A finite element model is established to analyze the influence of different base stiffnesses and bending-shear ratios on the bending shear composite buckling stress.The results are compared with the web buckling test result of a semi filled steel box concrete composite beam in the negative moment region.The results show that the rigid foundation of semi filled concrete can be simplified as an elastic foundation with a stiffness coefficient slightly lower than 5.