Research On The Mechanical Performance Of High-strength Bolted Connections With Flange Tapping

Compared with the traditional high-strength bolt connection,the flange tapping high-strength bolt connection can not only significantly improve the applicability and efficiency of engineering construction,but also has its advantages of good mechanical properties,energy consumption and seismic resistance.It is widely used in steel-like building.At present,the domestic and foreign researches on this new type of connection mainly focus on the research of unidirectional tension and unidirectional shear;few studies have been carried out on the composite force of tension and shear.Therefore,in view of the stress characteristics of flanged high-strength bolt connections,this article carried out a series of studies with its unique tapping steel plate and bolt tooth bite force mechanism as the research object,and achieved the following research results:(1)The refined finite element model is used to simulate the existing one-way stress connection test of flange tapping high-strength bolts.The comparison results show that the finite element analysis method used in this paper can better simulate the test process and can be applied to actual engineering and Parameter analysis.(2)Based on the energy intensity theory and the geometric characteristics of the tapping steel plate,the composite stress and failure characteristics of the tapping steel plate tooth body under different angles were studied,and the composite stress analysis model of the tapping steel plate tooth body under the most unfavorable stress state was proposed.A theoretical formula for the strength of tapped steel plate teeth based on bending shear failure is established.In order to give full play to the strength of the tensioned connection of flanged high-strength bolts,the minimum tapping plate thickness formula based on the necking failure of the bolts of high-strength bolts is proposed;Refined finite element analysis was conducted to study the failure modes,peak bearing capacity and deformation of M16 and M20 series bolts under different tapping steel plate thicknesses,and to verify the validity of the minimum tapping steel plate thickness formula,which can be applied to practical engineering.(3)Based on the characteristics of the force and deformation of the flange tapping high-strength bolts in one-way tension and unidirectional shear connection,the uneven force factors ? and η of the bolt teeth are introduced respectively,and the flange tapping high-strength bolts are unidirectionally stressed The design value formula of the bearing capacity of tensile,unidirectional shear and tensile shear composite joints.Through refined finite element parameter analysis,the non-uniform stress coefficients ? and η were determined to be 1.09 and 0.86,respectively;and the correctness of the formula for the bearing capacity design value proposed by theoretical analysis was verified,which can be used for practical engineering reference.