波形钢腹板组合箱梁体外预应力应力增量及模型试验研究

发布时间：2018-02-25 19:12

本文关键词： 波形钢腹板体外预应力应力增量模型试验有限元分析　出处：《兰州交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：将波形折叠的钢板用作箱梁的腹板,从截面形成来说是一种创新性的组合结构,即波形钢腹板组合箱梁。波形钢腹板组合箱梁桥具有诸多传统箱梁桥所不具有的优点,也有一些固有的缺点。随着此类结构的研究改进和施工技术的改善,这类桥受到了国内外设计建设者和研究者的青睐。然而,从现有资料看,对波形钢腹板组合箱梁体外预应力的研究较少。本文在参阅国内外大量试验研究资料、设计规范以及相关文献的基础上,进行了波形钢腹板组合箱梁模型试验体外预应力筋的分析研究,推导了基于挠度的体外预应力应力增量计算公式。此外,用大型有限元软件MIDAS/FEA建立波形钢腹板组合箱梁有限元模型,对波形钢腹板组合箱梁的试验梁和有限元模型值进行对比,进行了加载全过程的应力增量的分析,以及影响波形钢腹板组合箱梁体外预应力增量因素的分析。主要工作包括以下几个方面:(1)查阅相关文献,了解波形钢腹板组合箱梁和体外预应力混凝土结构构造以及目前国内外的发展研究现状。(2)介绍了波形钢腹板组合箱梁桥的基本力学性能和与体外预应力筋应力相关的理论。(3)进行波形钢腹板模型试验梁的精心设计、制作及静载试验。试验中主要进行了不同工况下梁的跨中挠度和体外预应力筋的应力值的数据采集,并对试验结果进行了分析。试验结果分析表明,在弹性阶段,梁跨中挠度和体外预应力筋的应力增量与荷载呈直线或近似直线关系。(4)根据体外预应力混凝土结构挠度和体外预应力筋应力增量变化关系,推导了直线布筋和折线布筋分别在不同荷载作用下的力筋应力增量计算公式。用推导出的体外预应力应力增量公式计算本次试验梁并与实测数据进行对比,对比发现结果很接近,这种计算公式对波形钢腹板组合箱梁体外预应力增量的计算是切实可行的。(5)通过选取合理的单元类型和材料属性,用MIDAS/FEA建立本次模型试验梁的有限元模型。有限元计算结果表明,软件计算结果和试验梁的实验数据分析结果相互吻合良好,这种波形钢腹板组合箱梁桥的建模方式是较为准确的。(6)用软件模拟了试验梁从一开始加载到结构破坏的全过程中体外预应力应力增量的变化情况,结果表明:结构在混凝土开裂前弹性阶段,体外预应力应力增量及跨中挠度与荷载呈线性关系;随着荷载的不断增大,混凝土开裂,跨中挠度和体外预应力应力增量增大较快,结构刚度明显降低,受拉区钢筋还处于弹性范围内,体外预应力应力增量及跨中挠度与荷载还呈线性关系;结构进入塑形阶段,受拉区钢筋屈服,挠度和体外预应力应力增量急剧增大,体外预应力应力增量及跨中挠度与荷载变为曲线关系。(7)用MIDAS/FEA建立影响波形钢腹板体外预应力筋应力增量不同参数的模型,通过分析了可知:对预应力增量影响大的因素为钢筋屈服强度、受拉区普通钢筋的配筋率及混凝土强度等级,而钢腹板厚度、钢材屈服强度、力筋张拉力和预应力配筋率对波形钢腹板体外预应力应力增量影响不大。
[Abstract]:The folding wave plate used as a box girder web, from the cross section form is an innovative composite structure, the composite box girder with corrugated steel webs. The box girder with corrugated steel webs has many advantages of traditional box girder bridge has not, there are some inherent shortcomings. With the improvement of technology and construction this kind of structure improvement, this kind of bridge by domestic and foreign design builders and researchers' attention. However, at present, the research of prestressed composite box girder with corrugated steel webs was less. In this paper refer to a large number of domestic and foreign research data base, design specification and related documents, the analysis of Prestressed composite box girder with corrugated steel webs model test in vitro, derived in vitro prestressed deflection based on stress increment formula. In addition, the establishment of corrugated steel webs with large finite element software MIDAS/FEA Beam finite element model of composite box of composite box girder with corrugated steel web beam test and finite element model were compared, the analysis of the stress increment of the whole process of loading, as well as the analysis of box girder with corrugated steel webs of external prestressed incremental factors. The main work includes the following aspects: (1) check the relevant literature, structure of composite box girder with corrugated steel webs and externally prestressed concrete structure and the domestic and international research status and development of understanding. (2) introduces the basic mechanical properties of box girder with corrugated steel webs and the theory of stress associated with external tendons. (3) a careful design model of corrugated steel web beams the making and the static load test. The main experiment conducted under different working conditions of beam deflection and stress of external prestressed tendons is the value of data acquisition, and the test results were analyzed. The test results Show that in the elastic phase, beam deflection and stress increment of external prestressed tendons is linear or approximately linear relation with the load. (4) according to the external prestressed concrete structure deflection and tendon stress increment, derived the calculation formula of straight line and broken line reinforcement reinforcement respectively under different loads the stress increment calculation. The test beam and compared with measured data with external prestressing derived stress increment formula, the comparison result is very close, the calculation formula of box girder with corrugated steel webs in vitro pre calculation of stress increment is feasible. (5) through the unit type and the reasonable selection of material properties, the finite element model of test beams with MIDAS/FEA finite element model. The calculation results show that the calculation results and experimental data of test beam analysis results are in good agreement with each other, this Modeling method for box girder with corrugated steel webs is more accurate. (6) use software to simulate the whole process of external prestressing test Liang Congyi began to destroy the structure of load changes, the results show that the stress increment before cracking in concrete structure in elastic stage, external prestress increment of stress and deflection with load is linear; with the increasing of load, the crack deflection and the stress increment of external prestressing increases faster, structural stiffness decreased, the tensile steel is in the elastic range, the stress increment of external prestressing and deflection and load is linear; structure into the shaping stage. The tensile steel yield, deflection and stress increment of external prestressing increases rapidly, prestressing stress increment and deflection and load change curve. (7) the establishment of effect of corrugated steel webs MIDAS/FEA In vitro prestressed tendons stress increment of different parameters of the model, through the analysis of the factors that affect the yield strength of steel for prestress increment, the tension zone of ordinary steel reinforcement ratio and concrete strength, and steel plate thickness, steel yield strength, tensile force of prestressed tendons and the reinforcement ratio of prestressed corrugated steel webs should not affect the stress increment in vitro.

【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.216

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