A Comprehensive Study on the Effect of Three Different Modeling Techniques and Pretension on Fatigue life of Bolts 2021-28-0186
For bolted joint design, the accuracy of decision made depends on several parameters like bolt pretension force used, 1D vs 3D bolt model, sub model vs full model and contact settings used for analysis. This paper discusses the effect of the above-mentioned parameters on bolts, thumb rules that can be used for designing and the parameters to be considered for decision making on the bolted joint design. The fatigue life of bolts subjected to all modelling techniques are calculated in this work and is used to compare between two different scenarios. All bolts are modelled with pretension. 3D bolts are modelled with surface to surface contact at the head and nut region. Among the 3D and 1D bolts, it was observed that the 3D bolts have a lesser change in pretension reaction force compared to 1D bolts. When the entire assembly model was compared to a sub-model including the bolts under consideration, it was found that both models have a close correlation with each other. Fatigue life of bolt with frictional contact applied at bolt head region was higher compared to a model with bonded contact at the same region. The paper also discusses the effect of different pretension values on the fatigue life factor of bolts.