Characteristics and bearing capacity of high-strength bolts


The high-strength bolt connection has the advantages of […]

The high-strength bolt connection has the advantages of simple construction, good stress performance, removable, fatigue
resistance, and no loosening under dynamic load, which is a promising connection method. High-strength bolts use special
wrenches to tighten the nuts, so that the bolts produce a huge and controlled pre-tension. The nuts and pads also produce the
same amount of pre-pressure on the connected parts. Under the effect of pre-pressure, a large frictional force will be
generated along the surface of the connected parts. Obviously, as long as the axial force is less than this frictional force,
the member will not slip and the connection will not be damaged. This is a high-strength bolt connection Principle. High-
strength bolt connection is to prevent the mutual sliding between the contact surfaces of the connecting parts. In order to
make the contact surface have sufficient friction force, it is necessary to increase the clamping force of the component and
increase the friction coefficient of the contact surface of the component. The clamping force between the components is
achieved by applying pre-tension to the bolts, so the bolts must be made of high-strength steel, which is why it is called
high-strength bolt connection. In high-strength bolt connections, the friction coefficient has a great influence on the bearing
capacity. Tests show that the friction coefficient is mainly affected by the form of the contact surface and the material of
the component. In order to increase the friction coefficient of the contact surface, methods such as sandblasting and wire
brush cleaning are often used to deal with the contact surface of the components in the connection range. High-strength bolts
actually have two types: friction type and pressure type. The criterion for friction type high-strength bolts to bear the shear
force is that the shear force caused by the design load does not exceed the friction force. High-strength bolts under pressure
are based on the design criteria that the shaft is not sheared or the plate is not crushed.

Contact Us