【作者】 蔡政；

【导师】 赵伟；

【作者基本信息】 江苏科技大学 ， 建筑与土木工程（专业学位）， 2018， 硕士

【摘要】 钢-混凝土组合梁能充分发挥钢与混凝土两种材料的优点,具有良好的整体性能及显著的成本效益,被广泛运用到实际工程中。但传统的钢-混凝土组合结构多为现浇,不适合预制装配施工,无法实现快速架设;传统的剪力键多为金属连接键按一定间距布置,由此带来的应力集中、传力不连续等问题较为突出。针对上述两个问题,本文提出了三种新型剪力键:(1)环氧砂浆胶结剪力键,(2)环氧砂浆外包栓钉混合剪力键,(3)高强度摩擦型螺栓剪力键。同时,为研究三类剪力键的受力性能,对采用此类剪力键的推出试件分别进行试验研究和有限元分析。本文主要进行了以下工作:(1)介绍了三类新型剪力键的试验目的、试验方法,试件的设计依据和设计思路。为得到试件所用材料的力学指标,进行了材性试验。(2)针对纯胶结剪力键进行了推出试验研究,详细描述了胶结剪力键的破坏过程与破坏形式,研究发现试件破坏均未发生在胶结层。并通过荷载-滑移曲线与极限抗剪承载力分析了此种连接方式的抗剪性能,得到此种剪力键的剪切强度能稳定达到工程要求。同时利用弹簧单元模拟胶结层的对试件进行有限元分析,并将模拟数据与实际推出试验数据进行对比,拟合了胶结厚度对胶结剪力键抗剪承载力的影响公式。(3)针对后浇栓钉剪力连接键进行了推出试验研究,分别从破坏形态、荷载-滑移曲线、极限抗剪承载力三方面对混合胶结与预制胶结两种剪力键进行对比分析,试验发现混凝土板预留孔径对试件抗剪承载力的影响。并结合多国规范,给出了环氧砂浆包裹栓钉时剪力键抗剪承载力的计算公式。(4)针对高强度摩擦型螺栓剪力键进行了推出试验研究,通过改变混凝土预留孔径、螺栓杆直径、预紧力等多种因素来研究此连接形式下试件的力学性能与滑移趋势。试验结果表明预紧力对试件整体力学性能影响明显,而增大螺栓杆径对提升试件承载力并无明显效果。通过有限元软件建立等比例模型进行了模拟,并将有限元模拟值与实际推出试验值进行了对比分析。本文对用于快速装配的新型剪力键进行了详细的研究分析,由此得出的系列结论和设计公式将进一步丰富装配式钢-混凝土组合结构桥梁的研究内容,为后续研究提供理论参考。更多还原

【Abstract】 The steel-concrete composite beam can give full play to the advantages of two materials,such as steel and concrete.It has good overall performance and significant cost benefit.It has been widely used in practical engineering.However,traditional steel-concrete composite are cast-in-place mostly and they aren’t suitable for prefabricated construction and cannot be erected quickly.The traditional shear connectors are mostly metal joint keys arranged in a certain distance,resulting in problems such as stress concentration and discontinuity of transmission force.In view of the problem,this paper puts forward three new shear connectors:(1)Cemented shear connector of epoxy mortar,(2)Epoxy mortar mixed stud shear connector outsourcing,(3)The bolt shear bond with high strength friction.At the same time,in order to study the mechanical properties of three kinds of shear connectors,the test and finite element analysis are carried out on the push out specimens using such shear connectors.The main work of this article is:(1)Introduced the purpose of test,the method of test,design basis and design idea of the three kinds of new shear connectors.In order to obtain the mechanical index of the material used in the test,the material property test was carried out.(2)According to the experimental study of the pure cemented shear connector,the failure process and failure form of the cemented shear bond are described in detail,and the failure of the specimen isn’t found in the cemented layer.The shear strength of this kind of connection is analyzed by the load-slip curve and the ultimate shear capacity.The shear strength of this shear connector can reach the engineering requirements.At the same time,the finite element analysis is carried out by using the spring element to simulate the cemented layer,and the simulation data are compared with the actual experimental data,and the influence formula of the cementation thickness to the shear strength of the cemented shear bond is fitted.(3)For the post cast stud shear connection key,the experimental study was carried out.from the three aspects of the failure form,the load slip curve and the ultimate shear capacity,the two shear bonds of the mixed cementation and the precast cementation were compared and analyzed.The effects of the reserved pore size of the concrete slab on the shear bearing capacity of the specimens were found.Combined with many codes,shear strength formula are given when bond epoxy mortar wrapped stud.(4)The experimental study on the shear bond of high strength friction bolt is carried out,and the mechanical properties and sliding trend of the specimens under this connection are studied by changing the concrete reserve diameter,the diameter of the bolt rod and the pretension force.The test results show that the pre-tightening force has an obvious effect on the overall mechanical properties of the specimen,while increasing the bolt diameter has no obvious effect on the bearing capacity of the specimen.The model was simulated by finite element software,and the finite element simulation value was compared with the actual test data.In this paper,a new type of shear connector used for rapid assembly is studied and analyzed in detail.The series of conclusions and design formulas will further enrich the research content of the assembled steel concrete composite structure bridge,and provide a theoretical reference for the follow-up research.更多还原