| High strength bolt occlusal connection is a new type of connection used in the field of support and hanger.It needs no drilling and is convenient to install.Due to the lack of relevant research,the shear capacity of high-strength bolt occlusal connection in engineering can only be determined by test at present,which is an expedient measure and needs to be solved theoretically.In order to find out the shear failure mechanism of high-strength bolt occlusal connection and give the calculation method of shear capacity,this thesis carries out the parameter analysis and research by the experimental method and the finite element method respectively.The test includes a single high-strength bolt occlusal type of the shear test and the typical connection of two parts of the shear test,a total of 96 tests,considering the channel steel section specifications and wall thickness,bolt specifications and installation torque of four parameters.The tensile test results of single bolts show that all the tests are toothed slot shear failure.When the installation torque reaches a certain value,it will not affect the shear bearing capacity.Nuts shall be of parallel teeth matched with channel teeth.The shear test results of typical connections show that all of them are toothed shear failure.The shear bearing capacity is twice that of a single bolt of the same type.It is shown that the single bolt shear test can reflect the bolt stress condition in the real situation.After comparing and verifying the finite element results with the test results,more than 100 finite element specimens of 8 series were designed for the shear strength of a single bolt.The influences of parameters such as material property,bolt size,pre-tension,chamfering,channel steel tooth depth,slope,tooth shape and shear area on the shear strength were analyzed.The finite element analysis results show that the pre-tension and the tooth profile of channel steel have almost no effect on the shear capacity.The bolt has no effect on the shear bearing capacity without deformation.The resistance shear capacity of channel steel has almost no effect when the tooth depth reaches a certain depth.The chamfering Angle and slope will affect the shear capacity.There is a linear relationship between the tensile strength,the shear area of channel steel teeth and the shear capacity,which directly determines the size of the shear capacity.Based on the results of test and finite element analysis,the theoretical calculation method and design suggestion for the shear capacity of high-strength bolted occlusal connection are given,and the comparative verification is carried out,which is safe and convenient to use,and can be used for reference by the support and hock engineering designers. |
