倒T形混凝土缺口梁抗弯性能的优化分析

Optimization Analysis of Inverted T-Shaped Concrete Notched Beams

为研究翼缘缺口对于倒T形混凝土梁力学性能的影响,设计了2根倒T形梁进行静力试验,通过对比两个试件承载力、破坏模式、裂缝发展、钢筋应力应变等方面进行分析。利用有限元软件ANSYS建模并验证合理性,以此为基础,定量分析材料强度、纵筋配筋率和箍筋间距等参数变化对于缺口梁力学性能的影响。结果表明:倒T形缺口梁完整侧翼缘在加载过程中逐步参与受压,试件破坏状态为典型的弯扭破坏,相对于完整倒T形梁,倒T形缺口梁的抗弯承载力明显下降,但具有更好的位移延性。减小箍筋间距、提高纵筋配筋率均能显著增加缺口梁的正常使用极限状态特征荷载和承载能力,提高缺口梁的抗弯刚度,减小结构变形,使缺口梁有效抵抗扭转。

To study the effect of flange notch on the mechanical properties of inverted T-shaped concrete beam,two inverted T-shaped beam were designed for static tests,and the bearing capacity,failure mode,crack development and stress and strain of reinforcement were analyzed by comparing the two specimens.The finite element software ANSYS was used to model and verify the rationality.Based on this,the influence of material strength,longitudinal reinforcement ratio and stirrup spacing on the mechanical properties of notch beam was quantitatively analyzed.The results showed that the intact flanks of the inverted T-shaped notched beam gradually participated in the compression during the loading pro-cess,and the failure state was a typical bending-torsional failure.Compared with the intact inverted T-shaped beam,the inverted T-shaped notched beam had a significantly decrease in flexural capacity,but showed a better displacement ductility.Decreasing the stirrup spacing and increasing the longitudinal reinforcement ratio could significantly increase the characteristic load and bearing capacity of the inverted T-shaped notched beam in normal service limit state,improve the flexural stiffness of the notch beam,reduce the structural deformation,and make the notched beam effectively resist torsion.