PVA-ECC对角斜筋小跨高比连梁试验研究及理论分析

发布时间：2018-06-10 08:36

本文选题：PVA-ECC + 小跨高比连梁　；参考：《西安建筑科技大学》2013年硕士论文

【摘要】：地震作用下，连梁可以首先屈服，通过塑性铰耗散地震能量，从而保护建筑物的主要承重部分—墙肢。相比于跨高比较大的细长梁或简支深梁，小跨高比连梁的受力和变形性能发生了很大变化。国内外学者主要通过新型配筋方案、新型截面形式和采用高性能混凝土这三个方面对小跨高比连梁的抗震性能进行研究。本文在对小跨高比连梁加设对角斜筋的基础上，采用新型材料PVA-ECC作为基体材料，将纤维良好的力学性能和构件的受力特性结合，使连梁构件具有良好的延性和耗能性能。通过对5个连梁试件的试验研究，得出这种连梁试件具有较高的承载能力和变形能力，满足强震下连梁的承载力和变形需求。本文的主要研究内容如下：（1）制作了4个PVA-ECC对角斜筋小跨高比连梁和1个普通混凝土对角斜筋小跨高比连梁，，并对其进行了低周反复水平荷载作用下的抗震性能试验。试验结果表明，PVA-ECC试件中纤维在裂缝出现后起到了很好的桥接作用，使得其承载力在斜筋压屈后可以继续提高，裂缝开展缓于普通混凝土，同时也提高了连梁的延性和耗能能力，在主斜裂缝出现前，PVA-ECC连梁已经具有较高的承载能力和变形能力，满足强震下连梁的承载力和变形需求。（2）利用有限元软件ABAQUS对试验结果进行了仿真分析，分析结果与试验结果比较吻合。在此基础上，对这种连梁进行了参数分析，研究了跨高比、基体抗压强度和配箍率对连梁承载力和变形的影响。结果表明，用PVA-ECC替代普通混凝土作为连梁基体材料，可有效提高连梁的延性和耗能能力，由于PVA-ECC具有单轴受拉应变-硬化性能及较高的拉伸应变，提高了斜拉杆的抗拉能力，使连梁的刚度退化减缓。最后将几种不同配筋、不同基体材料连梁与已有试验结果对比，进一步验证了PVA-ECC小跨高比连梁良好的抗震性能。
[Abstract]:Under earthquake, the connecting beam can yield first and dissipate seismic energy by plastic hinge, thus protecting the main load-bearing part of the building, the wall limb. Compared with the slender beam or simply supported deep beam with large span height, the mechanical and deformation behavior of the small span / height ratio continuous beam has changed greatly. The aseismic behavior of small span ratio connecting beam is studied by three aspects: new reinforcement scheme, new section form and high performance concrete. In this paper, on the basis of adding diagonal skew tendons to small span / height ratio connecting beams, a new material PVA-ECC is used as matrix material, which combines the good mechanical properties of the fibers with the mechanical properties of the members, so that the connecting beam members have good ductility and energy dissipation performance. Through the experimental study of five continuous beam specimens, it is concluded that this kind of continuous beam specimen has higher bearing capacity and deformation capacity, which can meet the bearing capacity and deformation requirement of connecting beam under strong earthquake. The main contents of this paper are as follows: (1) four PVA-ECC beams with small span to height ratio and one common concrete beam with small span to height ratio are made, and the seismic behavior of the beams under low cyclic horizontal load is tested. The test results show that the fiber in PVA-ECC specimens plays a good bridging role after the cracks appear, so that the bearing capacity of PVA-ECC specimens can continue to increase after the bending of oblique tendons, the crack development is slower than that of ordinary concrete, and the ductility and energy dissipation ability of the connecting beams are also improved. PVA-ECC beams have high bearing capacity and deformation capacity before the occurrence of the main oblique cracks, which can meet the bearing capacity and deformation requirements of the beams under strong earthquakes. (2) the test results are simulated and analyzed by using finite element software Abaqus. The analytical results are in good agreement with the experimental results. On this basis, the effects of the ratio of span to height, the compressive strength of matrix and the ratio of hoop on the bearing capacity and deformation of the connecting beam are studied. The results show that PVA-ECC can effectively improve the ductility and energy dissipation ability of the connecting beam by replacing ordinary concrete as the matrix material. Because PVA-ECC has uniaxial tensile strain-hardening property and high tensile strain, it can improve the tensile ability of the inclined drawing rod. The stiffness degradation of the connecting beam is reduced. Finally, by comparing the experimental results of several kinds of reinforced beams with different matrix materials, the good seismic performance of PVA-ECC beams with small span height is further verified.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU973.31

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