钢桥设计方法及应用的研究-桥梁与隧道工程专业论文.docxVIP

摘 摘 要 钢桥的设计方法按其设计理论大体可分为弹性设计方法和塑性设计方法。本 文通过对比容许应力设计法，荷载系数设计法及自应力设计法，探讨了塑性设计 方法的特点及其特点的工程应用。 针对钢结构进入自适应状态只是应力超过弹性极限值，随着载荷的重复作 用，只引起弯矩、应力等的弹性交化，结构的塑性变形保持为常值的一种稳定的 弹性行为，而不引起结构破坏。提出利用自动适应状态这一特性对连续钢梁桥进 行更经济合理的设计，对既有旧钢桥进行更符合实际的评估都具有十分重要的意 义，并且研究了应用的基本方法。此外利用塑性内力重分布理论设计还可以减少 超静定结构的用钢量，较为经济实用；利用塑性设计方法对桥梁运营阶段，超载 阶段和最大载阶段的截面的验算，能较真实的评估新旧钢板梁桥的承载力。 另外在研究弹塑性有限元法和力学知识基础上，利用大型有限元分析软件 ANSYS对连续钢梁进行弹塑性分析，使塑性设计法的理论依据得以验证，并使认 识更为直观。 本文通过论述揭示了塑性设计方法的重要价值和推广应用的基本途径。 关键词；钢桥塑性设计自适应弹塑性有限元法有限元软件ANSYS AbstractAccording Abstract According to the basic design theory,the bridge design method can be divided into the elastic design method and the plastic method．Throu出contrasting the tolerance stress design method，the load factor design method and the autostress design method， this paper discusses the characteristics ofthe plastic design method and applications of these characteristies． Aiming at the self-response of the structures which is just a kind of elastic stable behavior：the stress exceed the elastic limit value，while it do not arose deslruetion of the structure；Under the alternate loading，it just arose elastic changes of the stress and the moments，while the plastic deformation ofthe structure keep in constant value．And SO the paper discusses methods to utinze the characteristics of self-response of the structures to design and evaluate carrying capacity ofthe steel continuous beam bridge． And it can economically reduce the cost of steel to use the plastic redistribution theory of internal force．Furthermore，it is practical to use the plastic design method to check the real carrying capacity ofthe section at normal loading stage，over-loading stage and the maximal loading stage． Besides that，on the basis of studying the elastic and plastic finite element method and mechanics knowledge，the paper analyze a steel continuous beam by the large analysis software ANSYS． Through the discussion，the paper illustrates the important meaning and general way t0 popularize the plastic design method and its