The difference between high-strength bolt friction type […]
The difference between high-strength bolt friction type and pressure type connection:
The high-strength bolt connection is to clamp the plate of the connecting plate by a large tightening pre-tension in the bolt rod, which is enough to generate a large friction force, thereby improving the integrity and rigidity of the joint. When subjected to shear force, according to the design and the The difference in force requirements can be divided into high-strength bolt friction type connection and high-strength bolt pressure type connection. The essential difference between the two is that the limit state is different, although it is
The same type of bolt, but in terms of calculation methods, requirements, scope of application, etc. are very different. In the shear design, the high-strength bolt friction type connection is the limit state that the external shear force reaches the maximum frictional force provided by the bolt tightening force between the contact surfaces of the plates as the limit state, that is, the inner and outer shear forces of the connection are not exceeded during the whole use period. Maximum friction. The plate does not undergo relative slip deformation (the original gap is always maintained between the screw and the hole wall), and the connected plate is subjected to the elastic force as a whole. In the shear design, the high-strength bolt pressure-type connection allows the external shear force to exceed the maximum friction force. At this time, the relative sliding deformation between the connected plates occurs until the bolt rod contacts the hole wall, and then the connection is made by the bolt rod. The shearing of the body and the pressure of the wall and the friction between the contact surfaces of the plates jointly transmit forces, and finally the shearing of the shaft or the pressure of the wall is used as the limit state of the connection shearing. In short, the friction type high-strength bolt and the pressure-bearing high-strength bolt are actually the same type of bolt, but the design is
No consideration of slippage. The friction type high-strength bolt can never slide, and the bolt does not bear the shearing force. Once it is slipped, the design is considered to be in a state of failure, and the technically mature; the pressure-bearing high-strength bolt can slide, the bolt also bears the shearing force, and the final damage is equivalent to ordinary Bolt breakage (bolt cut or steel plate crush).