In our experience bolted joints are often missed in structural assessments, but they are of crucial importance with respect to structural integrity and are quite often the design driving features.

Bolted joint calculation is undertaken as a FEA post-processing activity by either our bespoke software coding or via the dedicated software MDESIGN depending on the safety category of the joint.
The loads in the bolts is often taken from FEA modelling where bolts are represented with BEAM elements from which elements force can be extracted for the calculations. Using the FEA model in this way combined with the use of part to part contact allows the automatic inclusion of any prying effects which would increase axial bolt load.

Calculation methods consider factors such as strength grade, torque tightening, elongation, embedding, slippage, bolt stress, bearing stress and fatigue. Calculations are conducted to design codes such as VDI2230 and EN 1993-1-8.