Modeling the tightening of a screw

4 October 2012

A new test-case ssnv228 illustrates the methodology for modeling the clamping (preload) of a screw or a stud.

Setting pretension consists of imposing a relative displacement between the nodes of the nut and the nodes of the stud. This relative displacement is imposed on the axis of the stud and must match the desired clamping force. This relative displacement is imposed via the keyword LIAISON_GROUP of the command AFFE_CHAR_MECA_F.

For the user, it is therefore necessary to determine the imposed displacement to find the desired clamping force. To do this, we must replaythe study several times by changing the value of the relative displacement until reaching the desired clamping force.

Example : Bolted pipe joints, geometry and mesh