FE Analysis of a Partially Trimmed Vehicle using Poroelastic Finite Elements Based on Biot's Theory

Bertolini, Clara; Gaudino, Ciro; Caprioli, Davide; Misaji, Kazuhito; Ide, Fumihiko

doi:10.4271/2007-01-2330

Cited by 16 publications

(3 citation statements)

References 6 publications

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“…In this method, each mode can be affected by the acoustic components but the effect on the coupling between the modes is neglected.  A third method, described in [2] and [4] consists in condensing the impedance matrix of the acoustic treatments to its degrees of freedom interfaced with the structure or the cavity. The condensed impedance matrix is then projected into the modal space and injected in the modal impedance matrix of the complete system.…”

Section: /19/2016mentioning

confidence: 99%

Vibro-Acoustic Modeling of a Trimmed Truck Cabin in Low Frequency Range to Tackle the Challenge of Weight Reduction

Acher¹,

Ege²,

Sandier³

et al. 2018

SAE Technical Paper Series

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In the challenge of reducing the weight of the vehicle structures, a particular focus has to be done on the interior noise. Indeed, the weight reduction of the structure often implies an increase of the noise in the cabin. To maintain a constant acoustic performance, acoustic packages often have to be added, the challenge being that the weight of the acoustic materials added remains lower than the weight saved in the structure. In today's engineering world, numerical simulation is the primary tool to assess the vibro-acoustic behavior of the vehicle during the design phase. To tackle the challenge of weight reduction, it is necessary to simulate accurately the vibro-acoustic response of the structure including the acoustic treatments. This paper presents the validation of a simulation method for the vibro-acoustic response of a truck cabin, taking into account the effect of acoustic treatments, in the frequency range [0-200Hz]. The method combined a modal scheme for the structure and the cavity with a physical scheme for the acoustic treatment (porous materials). The model consists in a truck cabin with its cavity and five acoustic treatments (three floormats, the headliner and the rear trim panel). A measurement campaign is performed to get reference NTFs, VTFs and local inertances. The model without any treatments is first correlated. The noise reduction given by each treatment alone as well as grouped together is simulated. The comparisons between the simulated and measured results show good agreement both in term of spectrum and amplitude. Although some discrepancies in the low frequency range remain unexplained, the method is considered as validated.

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Section: /19/2016mentioning

confidence: 99%

Vibro-Acoustic Modeling of a Trimmed Truck Cabin in Low Frequency Range to Tackle the Challenge of Weight Reduction

Acher¹,

Ege²,

Sandier³

et al. 2018

SAE Technical Paper Series

View full text Add to dashboard Cite

show abstract

“…For vehicle development, the normal modes analysis shall be performed on the BIW structures as well the trimmed body [8]. The trimmed body is referring to the BIW with added damping treatments and trim part [9]. The modal analysis for BIW and trimmed body is normally performed in free-free condition where no constrain is applied on the model that may lead to rigid body motion.…”

Section: Normal Mode Analysismentioning

confidence: 99%

Preprocessing and Solving Finite Element Analysis for NVH Prediction

Talib

Husain

Fauzi

2013

AMM

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Current vehicle development period has become shorter; therefore, virtual testing has been considered as vital to assist design decision at the early stage of the development. Over the last three decades, Finite Element Method (FEM) is widely used to predict the Noise and Vibration level of a vehicle. With the latest technology of Computer Aided Engineering (CAE) simulation, the calculation time taken for NVH analysis can be reduced from few days to only few hours. This paper presents current simulation technique for automotive development using Altair Hyperworks as preprocessing tool for vehicle modeling as well as application of NASTRAN as calculation solver. Normal Mode analysis is conducted on the Trimmed Body to investigate the natural frequency of the steering and the vehicle resonance. The result obtained is comparable with the actual prototype testing result to present the level of correlation. Coupling structural-acoustic analysis also conducted to predict the Noise Transfer Function (NTF) at the driver's ear.

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“…The development of the numerically efficient mixed (u,p) formulation for poroelastic material by Atalla et al with only 4 degrees of freedom per node (instead of 6 for the former (u,U) formulation) and its finite element implementations on the first commercial softwares gave a real start to large scale industrial applications [6,7]. Except for the case of simplified setups like the RTC III, most of the industrial applications with partially trimmed or almost fully trimmed vehicles were carried out in the low frequency range up to 400 Hz typically [8,9,10,11,12].…”

Section: Introductionmentioning

confidence: 99%

Trim FEM simulation of a dash and floor insulator cut out modules with structureborne and airborne excitations

Duval

Baratier

Morgenstern

et al. 2008

The Journal of the Acoustical Society of America

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During a vehicle development, measurements on cut out modules in large coupled reverberant rooms are often carried out in the middle and high frequency range in order to optimize the insulation performance of the trims (Transmission Loss). Using optimal controlled mounting conditions, we have been able to extend the frequency range to the low frequencies in order to validate trim FEM models of a dash and floor insulator modules with structureborne and airborne excitations. Both coupled response with movable concrete cavities (structureborne excitation) and Transmission Loss with the coupled reverberant rooms (airborne excitation) have been measured and simulated for various types of insulators on the same setup, without any change on the mounting conditions. An additional movable absorbing environment in the large reception room has been deployed in order to carry out laser vibrometer (skeleton velocity) and p-u probes (particle velocity and intensity) measurements on the surface of the trims. By incorporating the maximal treatment mock-ups of the cut out modules as additional trims in the models, we have obtained good correlation results between measurements and simulations for both bare and trimmed configurations for a dash and floor insulators with structureborne and airborne excitations.

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FE Analysis of a Partially Trimmed Vehicle using Poroelastic Finite Elements Based on Biot's Theory

Cited by 16 publications

References 6 publications

Vibro-Acoustic Modeling of a Trimmed Truck Cabin in Low Frequency Range to Tackle the Challenge of Weight Reduction

Vibro-Acoustic Modeling of a Trimmed Truck Cabin in Low Frequency Range to Tackle the Challenge of Weight Reduction

Preprocessing and Solving Finite Element Analysis for NVH Prediction

Trim FEM simulation of a dash and floor insulator cut out modules with structureborne and airborne excitations

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