2. Determination of stiffnesses

In the first part of this report, we treated bolts and parts as springs, i.e., we assumed that the axial stiffness of the various components of the assembly were characteristic constants of the component in question.

This simple model enabled us to analyze the specific behavior of a preloaded assembly, which is essential knowledge for an engineer designing mechanical assemblies.

We also highlighted that, in order to calculate the resistance of the screw in static conditions and, above all, in fatigue conditions, it was necessary to accurately assess the various stiffness parameters.

This knowledge is also essential in order to correctly model screw connections at angles (see [BM 5 566] ).