Segment-to-segment contact elements for modelling joint interfaces in finite element analysis

This paper presents an efficient approach to model contact interfaces of joints in finite element analysis (FEA) with segment-to-segment contact elements like thin layer or zero thickness elements. These elements originate from geomechanics and have been applied recently in modal analysis as an efficient way to define the contact stiffness of fixed joints for model updating. A big advantage of these elements is that no global contact search algorithm is employed as used in master–slave contacts. Contact search algorithms are not necessary for modelling contact interfaces of fixed joints since the interfaces are always in contact and restricted to small relative movements, which saves much computing time. We first give an introduction into the theory of segment-to-segment contact elements leading to zero thickness and thin layer elements. As a new application of zero thickness elements, we demonstrate the implementation of a structural contact damping model, derived from a Masing model, as non-linear constitutive laws for the contact element. This damping model takes into account the non-linear influence of frictional microslip in the contact interface of fixed joints. With this model we simulate the non-linear response of a bolted structure. This approach constitutes a new way to simulate multi-degree-of-freedom systems with structural joints and predict modal damping properties.