考虑滑移效应的体外预应力波形钢腹板梁桥的应力增量

体外预应力筋的应力增量在波形钢腹板梁桥理论中至关重要。在已有的应力增量计算方法中，适用于波形钢腹板梁桥的方法相对较少，考虑预应力筋滑移效应的更少。为研究适用于波形钢腹板组合梁体外预应力筋应力增量的计算公式，考虑在转向块处体外预应力筋与混凝土之间滑移效应的影响，通过分析预应力筋的变形和结构整体变形的几何关系，推导出对称荷载作用下的应力增量计算公式。结合现有试验数据，利用Ansys建立了实体模型，使用非线性弹簧单元Combin39来实现预应力筋的滑移效应；并将求得的计算值与试验值和模型值进行比对分析。结果表明：推导的应力增量公式计算值与波形钢腹板组合梁试验值吻合较好，验证了该方法的适用性；考虑滑移效应影响时，结构的整体挠度和应力增量增大，承载能力降低。

Stress increment of externally prestressed corrugated steel web girder bridge considering slip effect

The stress increment of the in vitro prestressing tendons is of critical importance in the theory of waveform steel web girder bridges. Among the existing stress increment calculation methods, there are relatively few methods suitable for corrugated steel web girder bridges, especially considering the slip effect of prestressed tendons. In order to study the calculation formula for the external prestressed tendon stress increment of composite beams with corrugated steel webs, this paper consider the influence of the slip effect between the external prestressed tendons and the concrete at the steering block. By analyzing the geometric relationship between the deformation of the prestressed tendons and the overall deformation of the structure, the calculation formula of stress increment under symmetrical loads is deduced. Combined with the existing test data, an entity model was established using Ansys, and the nonlinear spring unit Combin39 was used to realize the slip effect of the prestressed tendons; the calculated value obtained was compared with the experimental value and the model value for analysis. The results show that: 1) The calculated value of the deduced stress increment formula is in good agreement with the test value of the corrugated steel web composite beam, which verifies the applicability of this method.2) When considering the influence of the slip effect, the overall deflection and stress increment of the structure increase, and the bearing capacity decreases.