预加力作用下PC箱梁桥局段应力分析
发布时间：2019-05-03 20:32
【摘要】：随着箱梁宽度的逐渐增大,采用悬臂施工的连续梁及连续刚构桥,在施工的前数个阶段中,即施工短悬臂状态,采用梁单元理论进行施工阶段验算结构响应的不适用性,逐渐引起桥梁界的关注。在短悬臂状态,采用梁单元理论得到的应力与结构实际应力分布的差别,如何正确模拟后张法预应力钢筋等问题,亟待形成系统的研究成果。因此,本文以短悬臂状态下桥梁在预应力荷载作用下的局部应力为研究对象,进行了较为深入的研究,希望进一步完善PC箱梁桥的设计理论和方法,同时为施工提供一定的借鉴和参考。本文对PC箱梁桥的设计和分析理论进行了系统的论述、对比与总结,研究表明在施工的短悬臂状态采用梁单元进行分析是不精确的,亦或是造成桥梁在后期运营过程中开裂的隐患。基于实体有限元数值模拟法来实现后张法预应力作用下PC箱梁桥局段应力分析的方法,本文以花卉大桥为背景对不同建模方式的要点进行了明确的阐述,可为工程建造提供指导性意见。通过采用两种不同的方式进行预应力钢筋与混凝土单元的节点耦合建立的AN SYS实体有限元分析模型与基于初等梁单元的M idas-civil模型数据对比,结果表明采用初等梁单元进行分析不能够准确反映截面应力的分布,由于截面宽度较大,同一截面高度上应力分布是不均匀的。为进一步修正初等梁单元模型的误差,采用有效翼板宽度理论进行修正。结果表明,此理论还是不能用来计算结构的应力水平,腹板纵向正应力与实体单元分析的应力吻合较好。为进一步验证实体有限元数据的可信度,与花卉大桥实桥的监控数据进行了对比。研究表明,采用半耦合方式建立实体单元的有限元模拟更能够准确模拟结构的应力分布。研究表明采用梁单元理论分析桥梁在预应力荷载作用下的局部应力引起的误差,应该引起足够的重视。
[Abstract]:As the width of box girder increases gradually, the continuous beam and continuous rigid frame bridge constructed by cantilever, in the first few stages of construction, namely, the short cantilever state of construction, adopts the beam element theory to check the inapplicability of structural response in the construction stage. Gradually aroused the attention of bridge boundaries. In the short cantilever state, the difference between the stress obtained by the beam element theory and the actual stress distribution of the structure, how to correctly simulate the pre-stressed steel bars after Zhang Fa, and so on, need to form systematic research results. Therefore, this paper takes the local stress of the bridge under the prestressing force as the research object under the condition of short cantilever, carries on the more in-depth research, hopes to further perfect the design theory and the method of the PC box girder bridge, At the same time, it provides certain reference and reference for construction. In this paper, the design and analysis theory of PC box girder bridge are systematically discussed, compared and summarized. The research shows that it is imprecise to use beam element to analyze the short cantilever state in construction. Or cause the bridge in the later stage of operation in the process of cracking hidden dangers. Based on the solid finite element numerical simulation method, the stress analysis method of the local section of PC box girder bridge under the action of post-Zhang Fa prestressing force is realized. In this paper, the main points of different modeling methods are clearly expounded on the background of the Flower Bridge. Can provide guidance for the construction of the project. The finite element analysis model of AN SYS entity based on the coupling of prestressed steel bar and concrete element is compared with M-idas-civil model based on elementary beam element in two different ways. The results show that the stress distribution of the cross-section can not be accurately reflected by the elementary beam element analysis. Because of the large width of the cross-section, the stress distribution at the same section height is not uniform. In order to further correct the error of the elementary beam element model, the effective fender width theory is used to correct the error. The results show that this theory can not be used to calculate the stress level of the structure, and the longitudinal normal stress of the web is in good agreement with that of the solid element analysis. In order to verify the reliability of the entity finite element data, the comparison is made with the monitoring data of the real bridge of the Flower Bridge. The results show that the finite element simulation using semi-coupled method can simulate the stress distribution of the structure more accurately. The results show that the error caused by the local stress of bridge under prestressed load should be analyzed by beam element theory, which should be paid more attention to.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.213
本文编号：2469250
[Abstract]:As the width of box girder increases gradually, the continuous beam and continuous rigid frame bridge constructed by cantilever, in the first few stages of construction, namely, the short cantilever state of construction, adopts the beam element theory to check the inapplicability of structural response in the construction stage. Gradually aroused the attention of bridge boundaries. In the short cantilever state, the difference between the stress obtained by the beam element theory and the actual stress distribution of the structure, how to correctly simulate the pre-stressed steel bars after Zhang Fa, and so on, need to form systematic research results. Therefore, this paper takes the local stress of the bridge under the prestressing force as the research object under the condition of short cantilever, carries on the more in-depth research, hopes to further perfect the design theory and the method of the PC box girder bridge, At the same time, it provides certain reference and reference for construction. In this paper, the design and analysis theory of PC box girder bridge are systematically discussed, compared and summarized. The research shows that it is imprecise to use beam element to analyze the short cantilever state in construction. Or cause the bridge in the later stage of operation in the process of cracking hidden dangers. Based on the solid finite element numerical simulation method, the stress analysis method of the local section of PC box girder bridge under the action of post-Zhang Fa prestressing force is realized. In this paper, the main points of different modeling methods are clearly expounded on the background of the Flower Bridge. Can provide guidance for the construction of the project. The finite element analysis model of AN SYS entity based on the coupling of prestressed steel bar and concrete element is compared with M-idas-civil model based on elementary beam element in two different ways. The results show that the stress distribution of the cross-section can not be accurately reflected by the elementary beam element analysis. Because of the large width of the cross-section, the stress distribution at the same section height is not uniform. In order to further correct the error of the elementary beam element model, the effective fender width theory is used to correct the error. The results show that this theory can not be used to calculate the stress level of the structure, and the longitudinal normal stress of the web is in good agreement with that of the solid element analysis. In order to verify the reliability of the entity finite element data, the comparison is made with the monitoring data of the real bridge of the Flower Bridge. The results show that the finite element simulation using semi-coupled method can simulate the stress distribution of the structure more accurately. The results show that the error caused by the local stress of bridge under prestressed load should be analyzed by beam element theory, which should be paid more attention to.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.213
【参考文献】
相关期刊论文 前2条
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2 付永强;张小水;胡成;;预应力混凝土结构施加预应力的Ansys模拟[J];工程与建设;2008年06期
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