Interface‐reduction for the Craig–Bampton and Rubin method applied to FE–BE coupling with a large fluid–structure interface

This paper deals with the dynamics of jointed flexible structures in multibody simulations. Joints are areas where the surfaces of substructures come into contact, for example, screwed or bolted joints. Depending on the spatial distribution of the joint, the overall dynamic behavior can be influenced significantly. Therefore, it is essential to consider the nonlinear contact and friction phenomena over the entire joint. In multibody dynamics, flexible bodies are often treated by the use of reduction methods, such as component mode synthesis (CMS). For jointed flexible structures, it is important to accurately compute the local deformations inside the joint in order to get a realistic representation of the nonlinear contact and friction forces. CMS alone is not suitable for the capture of these local nonlinearities and therefore is extended in this paper with problem-oriented trial vectors. The computation of these trial vectors is based on trial vector derivatives of the CMS reduction base. This paper describes the application of this extended reduction method to general multibody systems, under consideration of the contact and friction forces in the vector of generalized forces and the Jacobian. To ensure accuracy and numerical efficiency, different contact and friction models are investigated and evaluated. The complete strategy is applied to a multibody system containing a multilayered flexible structure. The numerical results confirm that the method leads to accurate results with low computational effort.

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“…In [8] a remark on the computation of TVDs for free interface methods (e.g., the Rubin method [2,27]) can be found.…”

Section: Joint Trial Vectors Based On Trial Vector Derivativesmentioning

confidence: 99%

A complete strategy for efficient and accurate multibody dynamics of flexible structures with large lap joints considering contact and friction

2016

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“…Static coordinates then change and one speaks about interface modes [5] or partial interface modes [6] if some interface coordinates are kept. An interesting overview can be found in [7] and in [8].…”

Section: Introductionmentioning

confidence: 99%

Optimal component mode synthesis for medium frequency problem

Herran

Nélias

Combescure

et al. 2010

Numerical Meth Engineering

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International audienceThe component mode synthesis (CMS) with fixed interface (denoted Craig–Bampton) method uses a combination of static and dynamic modes. The usual definition of this CMS leads to a coupling between static and dynamic modes which are not orthogonal with respect to the stiffness matrix. This type of basis is not well suited for dynamic explicit computations, because the resulting mass matrix is not diagonal. If one keeps the same basis mode set but uses an orthogonalization process with respect to the mass matrix, the quality of the reduced Craig–Bampton system is kept but the basis vectors are combined differently. The aim of this paper is to propose a new way to control the accuracy of the reduced dynamic system for a specific frequency domain. Thus a new CMS is defined in order to be accurate in the medium frequency range

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“…Noise reduction is performed in industrial applications by using additional treatments such as porous material on the walls or viscoelastic material on (or inside) the structure . The computational time may be reduced by the use of modal basis , subdomain decomposition , or simplification of the absorbing material as rheological devices . Moreover, the accuracy of the numerical solutions may be controlled to ensure the quality of the results .…”

Section: Introductionmentioning

confidence: 99%

The extended finite element method combined with a modal synthesis approach for vibro-acoustic problems

Legay

2014

Int. J. Numer. Meth. Engng

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SUMMARYThe optimization of a vibro-acoustic problem is of main importance for passengers' comfort in transportation vehicles in terms of interior noise. Engineers use numerical tools to predict the response of this coupled problem, but it may lead to a prohibitive computational time. Based on FEM, this work aims at reducing the computational time. The first idea is to keep the same mesh of the acoustic cavity for all the structure configurations and to enrich the pressure approximation by using the extended FEM (XFEM). The enrichment is based on a Heaviside function completed at the structure tip by a continuous ramp function. The second idea is to build reduced basis. The structure basis is composed of its eigenmodes, whereas a modal synthesis method with a fixed interface is used to build the fluid basis. The interface DOFs are the enriched DOF of the XFEM, whereas the internal domain corresponds to the acoustic cavity with no structure. These two combined ideas enable to minimize the computational time in the study of the influence of the structure positions in an acoustic cavity. The method is implemented for shell structures embedded in a 3D acoustic domain.

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Interface‐reduction for the Craig–Bampton and Rubin method applied to FE–BE coupling with a large fluid–structure interface

Cited by 28 publications

References 35 publications

A complete strategy for efficient and accurate multibody dynamics of flexible structures with large lap joints considering contact and friction

A complete strategy for efficient and accurate multibody dynamics of flexible structures with large lap joints considering contact and friction

Optimal component mode synthesis for medium frequency problem

The extended finite element method combined with a modal synthesis approach for vibro-acoustic problems

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