Simplified model for the transient dynamic analysis of bolted assemblies

Bolted joints are crucial in assembly structures, particularly due to the high stresses and complex non-linear behaviours they experience. These joints are common in mechanical engineering applications, notably in aeronautics, where a single aircraft like the A380 can contain up to 3 million bolted connections.

Optimizing bolted joints requires sophisticated design strategies to address specific connection phenomena, including contact interactions, friction, and plastic deformation. However, performing transient dynamic analysis on detailed 3D models remains computationally prohibitive. Although commercial finite element (FE) software offers various simplified models, these are often limited in scope or challenging to configure, particularly for transient dynamics [1].

This study introduces an extension of a non-linear connector model [2] that accurately represents bolted connections in transient dynamic simulations. The goal is to lower computational costs while maintaining sufficient accuracy for key macroscopic metrics. Implemented as a user-defined element in Abaqus/Standard, this connector model integrates essential design parameters, such as bolt preload, friction coefficient, and bolt geometry. The model's axial behaviour accounts for preload effects and axial stiffness, while its tangential behaviour represents frictional interactions through an elastoplastic friction analogy. The connector's performance within a transient dynamic context will be evaluated, with the objective of future implementation as a user element in explicit codes like Abaqus/Explicit. This presentation will explore the impact of non-linear dissipation, preload, and mass distribution on transient responses, comparing results from fine-scale 3D simulations with those obtained using the connector model on bolted assemblies.