A fixed point algorithm and model reduction in jointed structures simulation

Abstract : The bolted joints have a strong impact on the damping and the stiffness of the structures. This impact remains difficult to predict because of the difference between the length scale of the real contact area and the wavelength of the vibration modes, and the uncertainties on the real geometry of the contact area. The method proposed in this paper is to divide the jointed structure into two parts : the linear part (L) and the non-linear one (NL) located around the joint. First, a linear analysis is performed on the global structure, neglecting dissipation inside the joint, to determine the normal modes of the structure. The normal modes subspace is normalized to the sti_ness matrix to associate to each eigenvectors the same strain energy. In the neighborhood of the bolted joint, eigenmodes are not orthogonal to each other’s. Thus, it is possible to reduce the size of the subspace spanned by the local eigenmodes. Moreover, most of them do not dissipate energy. Thus, it is possible to select the only ones that inuence the joint behaviour. We introduce the Principal Joint Strain Basis (PJSB) which is the optimal Ritz basis deduced from the structure eigenmodes, and simplified thanks to the analysis of the dissipation potential of each eigenmode. The dissipation potential is estimated by the energy coupling in the joint computed from the sensitivity of the eigenfrequency to the tightening configuration, i.e. when the surfaces of the interface are tied or when the tightening is very low. Then, we assume that a metamodel is able to represent the behaviour of the joints. In order to build it, we apply the PJSB as a loading on a finite element model of the joint and we post-process the results in order to use them in a reduce order model.
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Conference papers
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https://hal.archives-ouvertes.fr/hal-02131347
Contributor : Dma Femto-St <>
Submitted on : Thursday, May 16, 2019 - 12:15:27 PM
Last modification on : Tuesday, June 11, 2019 - 2:17:14 PM

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  • HAL Id : hal-02131347, version 1

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Nicolas Peyret, Gael Chevallier, Anthony Meurdefroid. A fixed point algorithm and model reduction in jointed structures simulation. Euro-Mediterranean Conference on Structural Dynamics and Vibroacoustics, Apr 2017, Sevilla, Spain. ⟨hal-02131347⟩

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