波形钢腹板组合T梁静力性能试验

为探索新型结构波形钢腹板组合T梁的受力性能，制作了下翼板布置直线型体内纵向预应力筋的缩尺试验梁，采用两点对称加载的方式开展了静载破坏性试验，对试验梁的截面正应变分布、荷载-位移曲线、开裂弯矩、剪应力分布、破坏形态、裂缝发展规律等进行测试。使用ABAQUS软件建立了试验梁的有限元模型，采用混凝土的损伤塑性模型和钢材的理想弹塑性本构对加载全过程进行非线性分析。基于钢-混组合梁的收缩、徐变理论和钢筋混凝土梁的抗弯承载力计算方法，对试验梁的开裂荷载和抗弯承载力进行理论计算。结果表明：只布置下翼板纵向预应力筋的波形钢腹板组合T梁的荷载-位移全过程曲线表现出较明显的弹性、弹塑性和塑性变形阶段，具有较大的抗弯刚度和良好的抗裂性和延性；抗弯承载力与开裂荷载的比值为1.79，具有较合理的承载受力特点；整个加载过程中，钢腹板与混凝土翼板变形协调，表现为典型的受弯破坏形态；剪应力在波形钢腹板组合T梁的腹板中分布均匀，可不设置弯起筋提供抗剪承载力；忽略波形钢腹板的轴向变形刚度和抗弯承载力，能准确计算开裂荷载和抗弯承载力；波形钢腹板组合T梁的力学机理明确，静力性能良好，具有工程应用前景。

Static Mechanical Properties of Composite T-girder with Corrugated Steel Webs

To analyze the mechanical performance of a composite T-girder with corrugated steel webs, a scaled test beam was manufactured with straight internal longitudinal prestressed tendons in a bottom flange. The static destructive test was performed by symmetrically loading of two concentrated loads. The distribution of normal strains in the section, load-displacement curves, cracking moment, distribution of shearing stresses, failure modes, and development of cracks of the test beam under loads were tested. The finite-element model of the test beam was built using the general FEA software ABAQUS, and the overall process of loading was analyzed through nonlinear calculations that were dependent on the damage-plastic model of concrete and the ideal elastic-plastic constitution of steel. The cracking load and the flexural resistance of the test beam were calculated based on the shrink and creep theory of steel-concrete composited beams and the flexural resistance calculation method of a reinforced concrete beam. The experimental, FEA, and theoretical analyses indicate that the overall load-displacement curves of the T-girder show elastic, elastic-plastic, and plastic stages. They also indicate that the test beam has large flexural rigidity, crack resistance, and ductility. The theoretical ratio of the flexural resistance to the cracking load is 1.79, which indicates it has rational carrying characteristics. The deformations of the steel webs and concrete flange are compatible over the whole loading process with no visible slip, and they demonstrate typical bending failure. Shear stresses are evenly distributed in the web of the composite T-girder, and needn't set the bending tendons to provide shear bearing capacity. Ignoring the axial stiffness and flexural capacity of corrugated steel webs, their cracking load and flexural resistance can be obtained accurately. The composite T-girder with corrugated steel webs with clear mechanical mechanism and good static performance has application possibilities in bridge projects.