【作者】 赵颖；

【导师】 贾艳敏；

【作者基本信息】 东北林业大学 ， 桥梁与隧道工程， 2008， 硕士

【摘要】 在钢结构中施加预应力可以改善结构的受力状态,增大结构的刚度,达到节约材料、降低造价的目的。近年来,预应力钢结构研究的工作主要是集中在预应力钢桁架、拉杆、压杆等方面,而对于预应力钢结构在桥梁工程中的应用则研究得较少。预应力钢梁是在普通的钢梁内设置高强度预应力钢索而形成的索梁共同受力的组合梁桥。首先,本文对预应力钢结构的种类和特点以及国内外发展概况进行了阐述,对有限元方法作了简要的介绍,对有限元建模中所使用的材料的屈服准则、材料的强化法则、材料的本构关系,以及双重非线性有限元方程的建立和求解方法做了详细的说明。其次,分别应用有限元软件ANSYS、MIDAS/Civil建立了普通简支钢箱梁和预应力简支钢箱梁的有限元模型,对其加载全过程进行仿真分析,并将有限元计算结果与实测数据进行对比分析,从而验证了所建有限元模型的正确性。通过对比利用ANSYS和MIDAS/Civil计算出的普通简支钢箱梁和预应力简支钢箱梁的极限荷载的数值,说明本文所计算出的极限荷载的数据是可信的。并利用ANSYS对曲线布索的预应力简支钢箱梁的荷载—位移曲线、正应力云图、跨中截面正应力、跨中截面应变、预应力钢索的张力增量进行了详细的分析,考虑了不同非线性因素对预应力钢箱梁的影响。最后,分析了预加力大小、梁的跨高比、双折线索水平段长度和预应力索的形状对钢箱梁由外荷载产生的跨中挠度、梁中应力以及钢索张力增量的影响。更多还原

【Abstract】 Exerting prestressing force among steel structure can improve mechanical state of structure, increase the rigidity of the structure, achieve the goal of saving materials, reducing the cost. In recent years, the research work in steel structure with prestressed tendons mainly concentrates on prestressing force steel truss, tension rod, compression bar, etc, but the study work to the application in the engineering of bridge building is less. A prestressed steel girder is regarded as composite structure of girder and tendons through establishing prestressed steel cable of high strength in the steel girder.Firstly, this text set forth the kind, characteristic, domestic and international development overview of the steel structure of prestressing force, introduced briefly the idea of finite element, and explained methods adopted in the model of finite element, which contains surrender criterion of material, strengthen rule of material, the relationship of stress and strain for material, and the foundation and solving of double non-linear finite element equations. Secondly, the finite element models of steel box girder and steel box girder with prestressed tendons were established by applying the finite element software ANSYS and MIDAS/Civil separately, introduced the simulation analysis of the whole loading process, and compared and analysed the calculating value and the experiment value, which proved the finite element model was right. The value of limit load, which was caculated by software ANSYS and MIDAS/Civil, was credible in this text through comparing the limit load of steel box girder and steel box girder with prestressed tendons. And this model is adopted to analyse loading-displacement curve, stress diagram, variation of stress at mid-span, variation of strain at mid-span, the increcement of tensile force of steel tendons, and considered the effect of different non-linear factors on the girder. Finally, factors that could have effect on the deflection at mid-span, the stress of the girder and the increcement of tensile force of steel cables, such as the prestressing force, ratio of span to rise, and the different cable layouts.更多还原