钢筋混凝土薄壁箱梁的非线性受力性能分析-桥梁与结构工程专业论文.docxVIP

摘要为进一步了解钢筋混凝土箱梁的非线性受力过程，本文采用非线性有限元理 摘要 为进一步了解钢筋混凝土箱梁的非线性受力过程，本文采用非线性有限元理 论对箱梁的受力过程进行了深入的研究，并在此基础上进行了参数分析。 本文首先概述了钢筋混凝土箱梁的受力特点及其在工程上的广泛应用情况， 总结了箱粱非线性研究的现实意义和国内外研究的状况及动态，提出了本文研究 的主要目的和主要内容。 对处于非线性阶段的钢筋混凝土箱梁，本文采用无闭锁的新型板壳单元与分 层法模型结合建立了钢筋混凝土箱梁的非线性受力模型，开发了非线性有限元程 序，将算例结果与其它方法的计算结果及试验结果作了比较分析，从而验证了所 采用的分析模型和分析方法及所开发程序的可行性。利用所开发的有限元程序详 细研究了钢筋混凝土薄壁箱梁从开裂、钢筋屈服直到破坏这一全过程中结构的受 力及变形特征，籍以分析各个阶段的结构受力反应和极限承载能力，并且对箱粱 的剪力滞效应进行了系统的参数分析。 采用按龄期调整的有效模量法本文还编制了箱梁徐变效应分析的有限元程 序，分析了混凝土徐变对箱粱的内力、变形、极限承载能力以及剪力滞的影响， 并着重分析了持荷时间、加载龄期、持续荷载大小对徐变效应的影响。 最后是本文的结论，总结全文，指出以后还需完善之处。 关键词：钢筋混凝土；箱梁；非线性；剪力滞；徐变 AbstractIn Abstract In order to find out its nonlinear behaviors deeply’the theoretical research and paranletric study on reinforced concrete thin-walled box-girder has been presented in this thesis based on the nonlinear finite element theory． First of all，the application and development of reinforced concrete box girder in the civil engineering are reviewed,and the state-of-the art about its nonlinear research at home and abroad has been summed up．Sequentially，primary research content and purpose of the thesis are put forward． Secondly,with the help of a new type of plate and shell element and the layered model to simulate the reinforced concrete nonlinear process under loading，a nonlinear finite element procedure has been developed．And the results obtained from the program shows a good agreement with those from the test，which demonstrates that the methods and program developed in this thesis are feasible and practical．The full range analysis from cracking to crashing of box girder are conducted in detail to ascertain the response for the structure to load，and the parametric study about the shear lag of box girder within the nonl协ear stage has been finished and some profitable conclusions have been cIbtailIed as well． Thirdly,in this thesis，the influence of concrete creep to the behaviors especially to the nonlinear behaviors of reinforced—concrete box girder has also been studied and the effect of creep