装配预制梁抗剪性能影响因素分析

Influence Factors Analysis of Shear Resistance Capacity of Prefabrication and Assembly Beams

为研究装配梁斜截面抗剪性能,设计了2根装配预制梁和1根整浇对比梁进行抗剪承载力试验,分析企口位置不同的装配预制梁的抗剪力学性能。采用有限元软件ADINA,建立6根装配预制梁模型,通过对设计的6根装配预制梁进行数值模拟,研究装配预制梁不同剪跨比和配箍率对抗剪承载力、构件破坏形态以及箍筋应力的影响。研究表明:在加载过程中,装配预制梁企口区域内的裂缝延伸较快,截面刚度有所削弱,但斜截面抗剪承载力特性和变形能力与整浇对比梁相似,开裂荷载和极限荷载与对比梁基本相同;钢筋混凝土梁抗剪承载力随剪跨比的增加而明显减小,而在其他参数相同时配箍率对抗剪承载力的影响较小。

In order to investigate the shear resistance capacity of prefabrication and assembly beam＇s cross section,two prefabrication and assembly beams and one cast-in-place RC beam were fabricated and the shear resistance capacity test of RC beam were carried out. The shear resistance mechanical properties of prefabrication and assembly beam with different cast-in dapped-end connections were analyzed. Combined with finite element analysis method,numerical simulation about six prefabrication precast beams was done. The effects of different shear span ratio and stirrup ratio on the shear resistance ultimate bearing capacity,failure pattern and stirrup stress were studied. The results show that： in the loading process,the cracks in the assembly area of the precast beam are more rapidly,and the section stiffness has weakened,but the shear resistance capacity and deformation capacity of the oblique section are similar to that of the whole beam. The shear resistance strength of reinforced concrete beams decreases obviously with the increase of shear span ratio,but the effect of strirrup ratio on the shear bearing capacity is small when the other parameters are the same.