Research On Structure Connection Performance Of GFRP Bolt

The traditional composite material bolt connection is mainly composed of a composite material plate and a steel bolt connection.In actual application,there are problems that the material properties of the two different materials are greatly different,and the steel bolts are easily corroded by the environment such as acid,alkali and salts.In recent years,composite material performance research and product development have developed rapidly.This article will study the performance of the new pultruded GFRP studs and the related connections using the studs.This paper takes pultruded GFRP studs as the main research object,through the performance test of pultruded glass fiber composites,the geometrical size of the joints,the shear resistance test of the pull-extruded GFRP single stud connection in conventional and corrosive environments The mechanical properties of glass fiber composite materials were studied,and the influence of material parameters,connection geometry parameters,usage factors and environmental factors of GFRP stud connections on composite material bolt connections was discussed,and the following conclusions were reached:1.Through the material performance test,the longitudinal tensile elastic modulus,transverse tensile elastic modulus and compressive elastic modulus of the pultruded glass fiber composite material used in this test were measured.2.The shear capacity of the pultruded GFRP studs with different nominal diameters used in this test was measured by the test of the shear capacity of the single stud shear connection in the conventional environment,and compared with the test in a corrosive environment.3.In the single-bolt connection,the pultruded glass fiber unidirectional laminate is mainly loaded by the fiber when it is loaded parallel to the fiber direction,and is mainly loaded by the substrate when it is loaded perpendicular to the fiber direction.In practical applications,pultruded glass fiber unidirectional laminates should pay attention to distinguish the fiber direction during use.4.The ratio of edge distance to hole diameter(E/D)and the ratio of width to hole diameter(W/D)of pultruded GFRP unidirectional laminates and studs in the bolt connection must first determine a lower limit to ensure that no plate breakage occurs Destruction and plate shear failure.However,due to the characteristics of high brittleness of the composite material and the concentration of stress at the edge of the hole,increasing E/D and W/D cannot increase the bearing capacity indefinitely.The laminated board will also undergo fiber delamination due to the limited bearing capacity of the matrix and adhesive.5.The factors affecting the shear capacity of pultruded GFRP studs are:1)Screw diameter.2)Processing technology.3)Thread depth.4)Destruction mode.6.Strong alkaline environment,acidic environment and chloride salt environment will cause the performance of pultruded GFRP studs to decrease,the bearing capacity will decrease,and the longer the contact time,the greater the impact.Among them,the strong alkali environment has the greatest impact on the pultruded GFRP studs.Not only will the performance of the studs be reduced,but also the fiber particles will fall on the surface of the studs.The threaded parts may even have gaps,which directly causes the studs to be unable to be installed and used.Figure 40 table 19 reference 26...