三维刚体弹簧元法在RC深梁抗剪性能尺寸效应评价中的应用

Applicability of 3D RBSM on evaluation of size effect for RC deep beam loaded in shear

选取典型的钢筋混凝土(RC)深梁受剪试验,开发并运用三维刚体弹簧元法(3D RBSM)模拟了大尺寸截面深梁的受剪破坏过程,以及箍筋对深梁抗剪性能的影响。结果表明,3D RBSM不仅能够较准确地计算RC深梁的开裂荷载、名义抗剪强度以及箍筋的增强作用,而且能够模拟裂缝的开展以及构件的破坏。相比于有限元法,3D RBSM具有以下优势:大幅度提高了名义抗剪强度的计算精度,实现了散布裂缝模拟的可视化以及混凝土裂缝宽度的直观、定量评价;能够更好地捕捉峰值荷载后的软化行为。因此,3D RBSM为大尺寸截面深梁的受剪破坏模拟、明晰抗剪性能尺寸效应机理和完善大尺寸RC构件设计提供了有效研究手段。

This paper validates the ability of three dimensional rigid-body-spring-method(3D RBSM)to simulate the shear failure behaviors of large crossse-ctional RC deep beams with and without stirrups.The numerical results prove that 3D RBSM not only can accurately reproduce the diagonal cracking load,normalized shear strength and the reinforcing effect of stirrups but also can simulate the deformation process and shear failure mode for RC deep beam.Compared with finite element analysis(FEA),3D RBSM has evident advantages:significantly improve the accuracy of normalized shear strength calculation,visualize the dispersed distribution of crack and quantitatively estimate crack width;has the capacity of reproducing the post-peak softening behavior.Therefore,it is concluded that 3D RBSM can be used to simulate the shear performance of large crossse-ctional RC deep beam,clarify the mechanism of size effect for shear strength and improve the shear design for large size RC members.