Fast computation of preloaded bolted circular joint aiming at fatigue bolt sizing Hypotheses and modeling

摘要

Purpose - This paper seeks to deal with a new modelization method which aims at fatigue sizing of preloaded bolted joints. Industrial design offices indeed need new models which, on the one hand, take bending of the bolts and geometrical non-linearity into account and, on the other hand, run fast enough to be used for preliminary design stages. Usual sizing procedures derive from VDI recommendations, which makes them inaccurate. On the contrary, classical finite element methods are revealed to be very costly. Design/methodology/approach - The first task lies in reducing the physical problem down and model the structure using axisymmetrical elements. Then, the core of the method lies in modifying the stiffness matrix of a tube element, in order to modify the axial compression stiffness to the one used by preloaded assembly classical computations. Eventually, a 2D finite element model is programmed which takes advantage of the modified element. A mounting was built to reproduce the typical loading of a slewing bearing. Experimental tests were carried out in order to help analyse the problem and to check finite element simulation results. Findings - Sample experimental results are presented which confirm the need for new models and validate the 2D model that was developed. Research limitations/implications - The new finite element, as well as the set of hypotheses that are used, appear to be usable for other bolted joints. Practical implications - A software was produced for the industrial partners, which is usable by non FE-specialists. Originality/value - This work may serve as a basis for building fast and accurate finite element models of other types of bolted joints.