Skip to Main content Skip to Navigation
Theses

Modèles d'articulations dissipatives en dynamique multi-corps

Abstract : Multibody simulations are used in the automotive industry to ensure that important design targets are met. A key point in the accuracy of such simulations is the proper modeling of rubber bushings and mounts. Indeed, they do require precise modeling of large deformation for high loading maneuvers, typically associated with active safety, and a correct modeling of dissipation, for most comfort applications. The current modeling process of these mounts and bushings considers tests to generate 0D models in each separate direction with linear viscous dissipation.The tests proposed and realized in this work were used to characterize the effects of large deformation, rate independent hysteresis and viscoelasticity separately. Models for each one of those behaviors are categorized into non-parametric models, extracted directly from data, selected order parametric models, whose accuracy depend on the number of internal states, and order independent models. Utilization of ratios of the nonlinear static branch for all the other branches is shown to be an effective way to model coupling of dissipation with large deformations. Transition between hysteresis and viscoelasticity is presented as a consequence of nonlinear viscoelasticity and provides good agreement with tests demonstrated by the comparison of the proposed instant modulus.The influence of loading in transverse directions on a given axis is very difficult to obtain from tests, yet necessary for accurate bushing models. Finite element computations are quite suitable for such studies, and as they require 3D models, the translation of the proposed 0D model into a 3D material model is detailed. Two different identification routines for both the 3D and 0D models were proposed: one with classic objective functions for the material model and a graphic one with order selection based on the non-parametric models. %Synthetic plots illustrating all behaviors are made for both material and part specimens, reuniting most of the responses.Despite the usefulness of FE routines to link geometry and material behavior, their typical computation times are orders of magnitude too large to be acceptable for the envisioned multibody applications. A combination of kinematic reduction and hyper-reduced integration of the model equations is thus detailed and shown to provide sufficient accuracy and the needed speedup in computation times. The mathematical frame for integrating the reduced 3D models into multibody routines is described.Finally, two multibody illustrations are detailed. The first case highlights the fact that hysteretic and viscous dissipations may lead to notably different transient responses, confirming the need for the propositions made for 0D models. The second one shows that replacing the current relatively coarse 0D models with those developed in this work should induce notable modifications of the response.
Complete list of metadata

https://pastel.archives-ouvertes.fr/tel-03678828
Contributor : ABES STAR :  Contact
Submitted on : Wednesday, May 25, 2022 - 3:59:40 PM
Last modification on : Wednesday, September 28, 2022 - 5:51:59 AM

File

penasferreira.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-03678828, version 1

Citation

Rafael Penas Ferreira. Modèles d'articulations dissipatives en dynamique multi-corps. Mécanique des matériaux [physics.class-ph]. HESAM Université, 2021. Français. ⟨NNT : 2021HESAE039⟩. ⟨tel-03678828⟩

Share

Metrics

Record views

45

Files downloads

20