中小跨度复合材料组合梁式桥梁结构及性能研究

发布时间：2018-05-14 00:26

本文选题：GFRP + 复合材料桥梁　；参考：《重庆交通大学》2014年硕士论文

【摘要】：纤维增强复合材料具有很强的可塑性和结构适应性，与钢材以及合金等金属材料相比，复合材料能够同时拥有质轻、比强度和比刚度高、耐腐蚀以及材料的可设计性等突出优点。近年来随着GFRP（玻璃纤维)产量和性能的提高以及成型工艺的日益成熟，GFRP在土木工程中的应用得到迅速推广但要作为桥梁工程的主要受力构件，还有大量的问题亟待解决，如：GFRP桥梁的结构形式、制造工艺、材料设计、构件连接方法等，这正是本文所涉及的研究内容和研究意义所在。本文对被广泛使用的拉挤成型工艺生产，纤维含量70%的e玻璃纤维/环氧树脂型GFRP进行拉伸、压缩试验，得出了其真实材料属性。探讨出合理的GFRP组合结构类型，提出较优的组合结构形式。采用该结构形式给出具有代表性的工程试例，给出其详细尺寸和参数，并对该桥的强度、刚度和稳定性进行了分析，表明该类桥具有强度高、稳定性好但刚度较弱的特点。通过对本文选用的GFRP型材进行市场价格调查和统计该桥的GFRP材料用量，表明该桥具备较好的经济实用性。针对本文探讨的GFRP复合材料组合结构，设计了合理的连接构造，并对不同连接方法的连接性能和破坏机理等进行了对比分析，结果表明：①GFRP与钢板胶接连接的破坏模式是胶层出现剪切破坏，导致连接失效。GFRP与钢板螺栓连接的破坏模式是螺栓孔出现剪应力集中，GFRP板在螺栓孔处剪应力过大，形成剪切破坏。GFRP与钢板胶-栓混合连接的破坏模式也是GFRP板在螺栓孔位置发生剪切破坏。②连接强度方面：胶-栓混合连接螺栓连接胶接连接。连接刚度方面：胶-栓混合连接胶接连接螺栓连接。连接延性方面：胶-栓混合连接螺栓连接胶接连接。③胶-栓混合连接中，螺栓的受力状态分为3个阶段：1)胶层产生塑性区之前，螺栓受力很小，荷载几乎全是由胶层承担；2)胶层产生塑性区但塑性区逐步扩展到螺栓孔之前，螺栓承担的荷载开始变大，但仍不作为主要受力构件；3)胶层的塑性区扩展到螺栓孔处，螺栓承担的荷载明显变大。此外由于胶-栓混合连接的复杂性和GFRP材料的特殊性，一些对螺栓连接或胶接有明显影响的因素（如螺栓个数、端距），对GFRP与钢板进行胶-栓混合连接的影响效果还有待进一步研究。通过有限元模拟分析，结果表明：①增加螺栓个数有助于提高胶-栓混合连接强度，但提升效果较微，，且单排螺栓数量不宜超过3个。②在胶层未产生塑性区之前，螺栓数量对胶-栓混合连接的刚度几乎没有影响；当胶层产生塑性区之后，螺栓数量越多连接刚度越高；螺栓数量与刚度不成正比关系，当单排螺栓数量超过3个之后，螺栓数量对连接刚度的影响可忽略不计。③端距对胶-栓混合连接的强度无明显影响，但对刚度的影响较显著。
[Abstract]:The fiber reinforced composites have strong plasticity and structural adaptability. Compared with metal materials such as steel and alloys, the composites can have light weight, high specific strength and specific stiffness at the same time. Corrosion resistance and the design of materials such as outstanding advantages. In recent years, with the improvement of GFRP (glass fiber) production and performance and the increasingly mature forming technology, the application of GFRP in civil engineering has been rapidly popularized, but as the main force member of bridge engineering, there are still a lot of problems to be solved urgently. For example, the structure form, manufacturing process, material design, component connection method of the GFRP bridge, which is the research content and significance of this paper. In this paper, the tensile and compression tests of e glass fiber / epoxy resin type GFRP, which is widely used in pultrusion molding and fiber content of 70%, are carried out, and the true material properties are obtained. The reasonable type of GFRP composite structure is discussed, and the better combination structure form is put forward. A typical engineering example is given in this paper. The detailed dimensions and parameters of the bridge are given. The strength, stiffness and stability of the bridge are analyzed. It is shown that this kind of bridge has the characteristics of high strength, good stability but weak stiffness. Through the market price investigation of the GFRP profile selected in this paper and the statistics of the GFRP material consumption of the bridge, it is shown that the bridge has good economic practicability. According to the composite structure of GFRP composite discussed in this paper, a reasonable connection structure is designed, and the connection performance and failure mechanism of different joining methods are compared and analyzed. The results show that the failure mode of the connection between GFRP and steel plate is shear failure of the adhesive layer, and the failure mode of the connection between GFRP and bolt is the shear stress concentration of the bolt hole and the excessive shear stress of the GFRP plate at the bolt hole. The failure mode of shear failure. GFRP and steel plate glue-bolt joint is also the shear failure of GFRP plate in bolt hole position. 2 connection strength: glue-bolt joint. Connection stiffness: glue-bolt joint bolt connection. Connection ductility: in glue bolt connection, adhesive connection, 3 glue and bolt hybrid connection, the stress state of the bolt is divided into three stages: 1) before the plastic zone is produced in the rubber layer, the force on the bolt is very small. The plastic zone of the rubber layer is almost entirely undertaken by the rubber layer. But before the plastic zone is gradually extended to the bolt hole, the load bearing by the bolt begins to become larger, but it is still not used as the main force member / unit / 3) the plastic zone of the rubber layer extends to the bolt hole. The load on the bolt is obviously increased. In addition, due to the complexity of binder bonding and the particularity of GFRP materials, some factors (such as the number of bolts) that have a significant effect on bolt connection or bonding, The effect of end-distance bonding on GFRP and steel plate is still to be further studied. Through finite element simulation analysis, the results show that increasing the number of bolts at 1 / 1 can improve the strength of the glue-bolt hybrid connection, but the lifting effect is relatively weak, and the number of single row bolts should not exceed 3. 2 before the plastic zone is produced in the rubber layer. The number of bolts has little effect on the stiffness of the joint; when the plastic zone is formed, the stiffness of the joint is increased with the increase of the number of bolts, and the number of bolts is not proportional to the stiffness, when the number of single row bolts exceeds 3, The effect of bolt number on the connection stiffness is negligible. 3. 3 end distance has no obvious effect on the strength of the glue-bolt joint, but it has a significant effect on the stiffness.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.216

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