COMPLAS 2023

Development of a simplified model for the transient dynamic analysis of bolted assemblies

  • Lançon, Quentin (LMPS - Laboratoire de Mécanique Paris-Saclay)
  • Guidault, Pierre-Alain (LMPS - Laboratoire de Mécanique Paris-Saclay)
  • Boucard, Pierre-Alain (LMPS - Laboratoire de Mécanique Paris-Saclay)
  • Vallino, Nicolas (Safran Tech)

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Bolted joints are essential components of assemblies as they are usually the site of significant stresses as well as numerous non-linearities. In addition, they are widely encountered in mechanical engineering, especially in aeronautics (e.g., 3,000,000 joints on an A380). Their optimization requires elaborate design strategies that take into account the specific phenomena at play within the connections (contact, friction, plasticity). Today, these optimizations can not be considered from 3D models in transient dynamics because of the prohibitive calculation costs involved. Of course, a wide range of simplified FE models is usually available in FE commercial code. However, they are either relatively limited or expensive to set up, especially in transient dynamic. This work proposes extending a non-linear connector model representative of a bolted connection to transient dynamic simulations. This approach aims at reducing computational costs while keeping a sufficient quality of representation concerning macroscopic quantities of interest. Based on design parameters (bolt preload, friction coefficient, bolt dimensions), the current connector is implemented as a user element in Abaqus/Standard. Axial connector behaviour automatically takes into account the preload effect and the axial bolt stiffness. Tangential connector behaviour models frictional phenomena that occur in the bolt thanks to an elastoplastic analogy for friction. In this presentation, its performances in the transient dynamic framework will be evaluated in order to eventually implement it as a user element in an explicit commercial code such as Abaqus/Explicit. In particular, the effects of non-linear dissipative phenomena, preload and mass distribution on the transient dynamic response will be studied. Comparisons between fine-scale 3D computations and simulations with connectors on bolted assemblies will be proposed.