【作者】 严辉均；

【导师】 何沛祥；

【作者基本信息】 合肥工业大学 ， 工程力学， 2007， 硕士

【摘要】 在桁架结构中，由于节点连接刚性以及节点板等可以导致次应力的产生，通过简单结构模型和全桥模型，对于由节点刚性所产生的次应力的影响因素和影响规律进行了讨论。对桁架桥中靠近支座处由于次应力过大的杆件需要进行截面复核。正交异性钢桥面板是由纵、横加劲肋和盖板组成并共同承受荷载的桥面结构。该结构最早始于二十世纪五十年代的德国，后来被很多国家广泛应用。目前已成为世界上大、中跨度钢桥所普遍采用的一种桥面结构形式。正交异性钢桥面板的受力复杂，我国公路桥涵钢结构设计规范未见计算规定及公式。正交异性钢桥面板的受力分析通常可归结为以下三个基本受力结构体系：作为主梁截面的一部分承受车辆运营荷载(第一结构体系)；由纵横向加劲肋组成桥面结构，承受车辆轮轴荷载(第二结构体系)；支承在纵横加劲肋上的钢盖板直接承受车辆轮载(第三结构体系)。传统的简化计算方法是把三个结构体系分别加以计算并进行应力叠加。正交异性板钢桥面系第二体系应力的计算方法主要有P-E法、等效格子梁法和有限元法等。在第二体系应力计算中，传统的简化解析法与采用现代计算机模拟的有限元法之间比较的问题被深入的研究和探讨。P-E法和等效格子梁法都是简化的解析法，都采用了一定的计算假定，而且对结构的边界条件有一定的要求，计算结果会产生一定的偏差，尤其是按支点最不利方式加载。而有限元法能较准确、有效地模拟实际结构，计算结果比较完整，有限元法是第二体系计算方法的发展趋势。但采用有限元法计算第二体系应力时中包含了一部分的第三体系应力。这就说明在现行的钢桥面系体系的划分中，采用有限元法计算会产生一定的误差。为了能让有限元法更好的应用，更好的与疲劳评估体系相结合，本论文提出了适合有限元法的钢桥面系体系划分的方法。更多还原

【Abstract】 Secondary stress arises because of the rigidity of joint and the nodal board, etc. Through simple structural model and integrity bridge model, the influence factors and the influence law of secondary stress induced by nodal rigidity are discussed. The components nearby support should be checked because of the secondary stress are excessive than others.Orthotropic steel deck consists of vertical beams, transverse beams and cover boards, and the loads are supported by all these parts. This structure firstly appeared in Germany in 1950s, And from then on this structure has been adopted by many country. Now it is a universally used bridge deck structure in large and middling span steel bride. Because orthotropic steel deck’s stress is very complicated, now domestic criterions prescript a proximate way to calculate this structure.Orthotropic steel deck is commonly partitioned into three basis systems: it is considered as a part of girder and supports the load (the first structural system); the longitudinal rids, the transverse rids and the cover board make up of the bridge surface (the second structural system); the third structural system is only made up of the cover board and support the wheel load. Traditional calculation method is to add the three systems’ stress.There are mainly three methods in the second system stress analysis of the orthotropic steel deck, P-E method, the equivalent girder beam method and the FEM. The Issue which is the most adaptive in three methods of the second system stress of the orthotropic steel deck has been studied and discussed.The P-E method and equivalent girder beam method are the simplified analysis ways, with some hypothesis. Their boundary conditions are strict, and the results are not precise, especially in the worst mode to the diaphragm. The finite element method can simulate the structure accurately, it is the trend of the computation of the second system stress of the orthotropic deck. But it’s result include the stress of the third system. In order to apply the finite element method and combine the fatigue estimation system the more conveniencely, the thesis put forward to construct a new system for the steel orthotropic deck.更多还原