体外预应力加固对梁长期刚度影响的分析研究

发布时间：2018-01-22 01:00

本文关键词： 体外预应力加固混凝土梁长期刚度有限元分析　出处：《苏州科技学院》2015年硕士论文　论文类型：学位论文

【摘要】：体外预应力加固具有轻质高强、受力明确、结构自重小、施工方便等优点,在建筑结构加固中应用广泛。因此,关于体外预应力加固技术的应用研究越来越多。但目前大部分的研究只考虑短期效应的影响,对加固梁长期效应影响的研究并不多。故需要对体外预应力梁长期效应的影响有全面的分析研究,为体外预应力加固技术提供理论支撑。本文主要针对影响体外预应力加固梁长期刚度的因素进行分析研究,主要考虑原梁约束、转向块个数、预应力筋的种类以及施加预应力大小等因素对加固梁长期刚度的影响,同时结合规范分析了惯性矩的不同、预应力筋贡献率等因素,给出加固梁长期刚度计算公式;根据相关假定对加固梁作长期荷载作用下的受力分析,推导出长期挠度的计算公式;通过工程实例加以验证;利用有限元分析手段,对各影响因素进行有限元分析。通过7根加固梁模型有限元分析,考虑了上述因素的影响,得到如下结论:原梁约束条件对长期刚度的影响很大,对支座处约束加强可以达到更好的加固目的;预应力筋的种类、张拉控制应力的大小、预应力筋的布置形式等,对于加固梁长期刚度的影响不一,其中预应力筋的布置形式影响最为突出,转向块的布置位置和个数对加固梁长期变形产生很大影响。本文联系实际,利用理论知识和有限元分析,得到体外预应力加固对梁长期刚度的影响规律,为以后此方面的研究提供参考,进而为工程实际应用提供理论依据。
[Abstract]:External prestressing reinforcement has the advantages of light and high strength, clear force, small structural weight, easy construction, and so on, so it is widely used in the reinforcement of building structure. There are more and more researches on the application of external prestressing reinforcement technology, but most of the current studies only consider the effect of short-term effects. There are few studies on the long-term effects of strengthened beams, so it is necessary to have a comprehensive analysis and study on the long-term effects of external prestressed beams. This paper mainly focuses on the analysis of factors affecting the long-term stiffness of externally prestressed strengthened beams, mainly considering the constraints of the original beam and the number of steering blocks. The influence of the type of prestressing tendons and the size of prestressing force on the long-term stiffness of strengthened beams is discussed. At the same time, the difference of moment of inertia and the contribution rate of prestressed tendons are analyzed in combination with the code. The calculation formula of long-term stiffness of strengthened beam is given. According to the relative assumptions, the calculation formula of the long-term deflection is derived by the analysis of the load on the strengthened beam under the long-term load. Through engineering examples to verify; By means of finite element analysis, the influence factors are analyzed. Through the finite element analysis of 7 strengthened beam models, the influence of the above factors is considered. The conclusions are as follows: the constraint condition of the original beam has a great influence on the long-term stiffness, and the reinforcement of the support constraint can achieve a better purpose. The types of prestressed tendons, the size of tensioning control stress, the layout of prestressed tendons and so on, have different effects on the long-term stiffness of strengthened beams, among which the influence of the layout of prestressed tendons is the most prominent. The location and number of steering blocks have a great influence on the long-term deformation of strengthened beams. In this paper, the influence of external prestressed reinforcement on the long-term stiffness of beams is obtained by using theoretical knowledge and finite element analysis. It provides a reference for the future research in this field, and then provides the theoretical basis for the practical application of engineering.
【学位授予单位】：苏州科技学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU37

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