Nguyen Dinh Han, Hong Won-Kee
Department of Architectural Engineering, Kyung Hee University, Yongin 17104, Korea.
Materials (Basel). 2019 Jul 18;12(14):2302. doi: 10.3390/ma12142302.
The purpose of the work was to propose analytical model considering double confinements (provided by both transverse reinforcements and a wide flange steel section), which was verified by the nonlinear finite element analysis considering concrete-damaged plasticity. The scope of the effort and the procedures to achieve the aim of this study included the identification of the concrete confinements provided by both transverse reinforcements and a wide flange steel section based on the elasto-plastic model in tension for both rebar/steel sections and elasto-buckling for rebars in compression. The influence of rebar buckling in the compression zone on flexural moment strength was also investigated with and without considering confining effects offered by steel sections. The analytical approach predicted a post-yield behavior of composite beams based on the confining effect offered by both the shear reinforcement and wide steel flange sections. However, for beams without axial loads, the compressive zones with high and partial confinements for concrete sections at the yield and maximum load limit state were limited when compressive buckling failure was not considered, preventing the confining factors from significantly influencing the flexural load resisting capacity. An accurate flexural capacity of composite beams can be obtained when rebar was modeled with buckling in the compression zone.
这项工作的目的是提出一种考虑双重约束（由横向钢筋和宽翼缘钢截面共同提供）的分析模型，该模型通过考虑混凝土损伤塑性的非线性有限元分析进行了验证。本研究为实现该目标所做的工作范围和步骤包括：基于钢筋/钢截面受拉时的弹塑性模型以及受压钢筋的弹性屈曲，确定横向钢筋和宽翼缘钢截面提供的混凝土约束。还研究了在考虑和不考虑钢截面提供的约束效应的情况下，受压区钢筋屈曲对抗弯强度的影响。该分析方法基于抗剪钢筋和宽钢翼缘截面提供的约束效应，预测了组合梁的屈服后行为。然而，对于无轴向荷载的梁，当不考虑受压屈曲破坏时，在屈服和最大荷载极限状态下，混凝土截面具有高约束和部分约束的受压区是有限的，这使得约束因素对抗弯承载能力的影响不显著。当对受压区的钢筋进行屈曲建模时，可以得到组合梁准确抗弯能力。
