Analysis of composite bolted joints by a macro-modelling approach

The purpose of this paper is the development and the assessment of detailed and macro-modelling methodology approaches, suitable for the analysis of composite material bolted joints.

A benchmark single-lap, single-bolt composite joint configuration is investigated, in order to demonstrate the different joint analysis approaches which are applicable in advanced riveted/bolted parts of aeronautical structures. In particular, several joint macro-models, i.e. numerical and analytical ones, as well as a detailed three-dimensional FE solid joint representation, were developed and compared in terms of stiffness prediction, while they were validated using respective experimental results. In addition, the numerical macro-model is implemented in a full scale, multi-bolt fuselage panel in order to demonstrate its capability to efficiently predict the panel’s response under compressive loads.

Good correlation was observed between the majority of the models’ predictions and the relative experimental data regarding the lap joint configuration, while the simplified numerical macro-model showed some discrepancies due to the contact instabilities, which, however, may be accepted taking into account the remarkable solution time reductions. In the same manner, the FE macro-model illustrates sufficient accuracy in the prediction of the panel’s response, while, simultaneously, it maintains a low CPU time.

The present study is part of Nikolaos Perogamvros’ doctoral thesis, an original research work. There are very limited literature papers which include the development and the assessment of different efficient and detailed composite joint analysis approaches, regarding their accuracy and efficiency in the stiffness prediction of a composite bolted joint configuration, as well as on the prediction of a multi-bolt panel’s response.