After nearly one year I have found some time to update my website. And I have tested the latest Fatlab version from http://fatiguetoolbox.org/ and customized it a little bit.
And I spend some time to recalculate the bolted joint example “Bolted_joint.zip” (https://sourceforge.net/projects/fatlab/files/examples). That is a pretty good example of nonlinear bearing load and bolt pretension.