Updating of the Dynamic Behaviour of an Assembled Structure with Bolted Joints in Light of EMA Results

Abstract

Bolted joints, which contribute significantly to minimise the magnitudes of resonant peaks of assembled structures and give easy-to-install and uninstall, have been widely used in various types of mechanical structural assembly and. However, modelling of an individual bolted joint within a large assembled structure has always been problematic, especially when it comes to predicting dynamic behaviour. The aim of this paper is to put forward an idea of efficiently and economically modelling of bolted joints of an assembled structure focusing on the bolting and assembly interfaces. The finite element (FE) models of individual components (Plate A and Plate B), bolting and assembly interfaces were developed using the NX11 Simcenter 3D software. Normal modes analysis was carried out for the initial FE models of the individual components and the assembled structure. Experimental modal analysis (EMA) was performed to determine the modal parameters of the individual components and assembled the structure. It was found that a low correlation between the initial FE models and EMA has been recorded. The initial FE models were then tuned in the light of EMA results in order to improve their accuracy and reliability. The proposed updating procedure has been successfully used in improving the low correlation which is largely due to the inaccurate modelling of the bolted joints.