内置H型钢预应力混凝土组合梁受弯性能非线性分析

Nonlinear Analysis of Flexural Behavior in Encased H-Steel Prestressed Concrete Composite Beam

目的研究内置H型钢预应力混凝土组合梁变参数、变形的受力性能,为工程设计及实践提供理论依据.方法应用ANSYS分析软件建立与试验梁相同的构件模型,通过模拟数据与试验数据的比对,验证有限元分析模型的可行性.以型钢于截面中的不同布置位置为变形式,以截面型钢含钢量及预应力度为变参数分别进行数值模拟.结果有限元分析数据与试验数据吻合较好;两种不同的型钢布置位置对开裂荷载和极限荷载影响不大;截面型钢含钢量变化对构件的开裂荷载、极限承载力和延性影响显著;预应力度对构件变形有重要作用.结论合理地建立有限元模型可较好地模拟内置H型钢预应力混凝土组合梁的受力性能;型钢于截面居中布置与型钢下移50 mm布置的模拟梁开裂荷载与极限承载力无显著变化,挠度相差将近30%;随着截面型钢含钢量的增大,模拟梁开裂荷载、极限承载力有大幅提高,延性系数减小,挠度受到限制;预应力度的增大致使构件的挠度减小.

The purpose of this paper is to further study the mechanical behavior of encased H-steel prestressed concrete composite beam with different parameters and forms, provide a theoretical basis for engineering design and practice. The authors used analysis software named ANSYS to establish the same models of beam components which are tested in the experiment, and to validate the feasibility of finite element analysis model through the comparison of the simulated data and experimental ones. The numerical simulation will analyze the beams with different H-steel arrangement in the section, different ratio of H-steel and prestressed degree. The results show that the finite element analysis data are in good agreement with the experi- mental ones;the different H-steel position of sections has little effect on cracking load and ultimate load;the different of H-steel ratio in the cross-section affects the cracking load, ultimate bearing capacity, and component ductility significantly ; prestressed degree plays an important role in deformation. Reasonable establishing the encased H-steel prestressed concrete composite beam could better simulate the mechanical behavior;there are no significant differences between cracking load and ultimate strength which the steel is in the center of the cross-section or 50 mm down from the center, however the deflection difference is nearly thirty percent; with the increase of H-steel ratio in the cross-section, the simulative beams get higher cracking load and ultimate strength,lower ductility coefficient;the deflection of the components reduce a lot with the increase of prestressed degree.