基于Timoshenko与高阶剪切变形梁理论的RC梁极限承载力分析

Ultimate Bearing Capacities of RC Beam Based on Timoshenko and Higher-order Shear Deformation Beam Theories

分别应用Timoshenko和高阶剪切变形梁理论,推导出能够考虑剪切变形的钢筋混凝土梁柱截面非线性分析模型,并提出应用横向正应变和剪应变的关系系数来计算混凝土开裂后的截面高度变形,采用基于修正斜压场理论的Stevens等的本构模型以避免混凝土的裂缝验算;数值模拟了正截面破坏以及集中荷载作用下有腹筋和无腹筋RC梁的极限承载力。结果表明:按2种理论计算的结果与试验数据吻合良好;基于Timoshenko梁理论的分析模型的结果更接近试验数据,收敛性也更好。

Based on Timoshenko and higher order shear deformation beam theories respectively, a nonlinear analysis model with shear deformation considered reinforced concrete （RC） frame element was deduced. To take into account the height deformation of the given member after diagonal cracking, a correlation between transverse normal strain and shear strain was proposed. The constitutive model proposed by Stevens, et al was adopted to eliminate the cracks checking of concrete, which was mostly based on modified compression field theory. Simulations about pure bending tests and concentrated loading tests with and without stirrups were made to validate the ultimate bearing capacity of RC beam. The results show that the calculation results based on the two theories are both in good agreement with experimental data. Comparatively, it is better to use the section analysis model based on Timoshenko beam theory to increase accuracy and computational efficiency, and the convergence is better.