Acoustic Optimization of a Power Take-off Gear Box Using Numerical Transfer Path Analysis

Wischmann, Stefan; Pasch, Gerwin; Berroth, Joerg; Jacobs, Georg

doi:10.1088/1757-899x/1097/1/012012

Cited by 3 publications

(1 citation statement)

References 4 publications

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“…Since the noise-vibration and harshness (NVH) behaviour of drivetrains is increasingly perceived as a safety and quality feature [3], a more differentiated approach in solving vibration problems is needed today. NVH models of many commonly used drive components are constantly being developed [4][5][6]. This development enables modelbased prediction and optimisation of systems in the development process.…”

Section: Introductionmentioning

confidence: 99%

Determining Dynamic Properties of Elastomer-Dampers by Means of Impact Testing

et al. 2022

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Background Damping elements made of elastomer materials are used in almost every mechanical system to prevent damage to components caused by impact-like excitations and the resulting high-frequency, large-amplitude oscillations. The dynamics of these operating conditions exceed the performance limits of conventional experimental testing methods, impeding validated predictions of the damper’s transmission behaviour. Objective A method is proposed to directly investigate the influence of impacts on the transmission behaviour of elastomeric dampers by impact testing. Methods Torsional-loaded elastomer dampers were experimentally investigated using a drop tower. During the experiment, a mass is brought into impact contact with a lever arm connected to the tested coupling. Measurements on resulting torsional oscillations and a comparison of the measurement results with a simple analytical model of the system allow for determining the coupling parameters stiffness and damping ratio. Results The characteristic parameters stiffness and damping ratio of the elastomer damper were mapped as a function of excitation-amplitude and frequency. A comparison of drop-tower test results with servo-hydraulic measurements validated the determined parameters. Conclusions Determining the transmission behaviour of elastomeric dampers from highly dynamic and impact-induced oscillation states proved to be a good approach to supplement established testing methods.

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Section: Introductionmentioning

confidence: 99%

Determining Dynamic Properties of Elastomer-Dampers by Means of Impact Testing

et al. 2022

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Recheneffiziente Quantifizierung parametrischer Unsicherheiten in NVH-Systemsimulationsmodellen mittels Sensitivitäts- und Unsicherheitsanalyse

Wischmann

Drichel

Jacobs

et al. 2023

Forsch Ingenieurwes

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The acoustic and structural dynamic properties of vehicles—often referred to as Noise, Vibration, Harshness (NVH)—form a crucial criterion during product development. To reduce iterations with physical prototypes, NVH simulation models are well established. In early development phases, many parameters of NVH models, such as material and contact properties, are either assumed based on empirical values or have to be measured. In both cases, the value of these parameters is uncertain. Thus, the output of NVH system simulation models such as structure borne or air borne sound is also uncertain and must be quantified. However, applying state-of-the-art uncertainty analysis methods to NVH simulation models considering all uncertain input parameters is inefficient due to their high computation time. Therefore, this paper presents a method of coupled sensitivity (SA) and uncertainty analysis (UA), which enables the efficient uncertainty calculation for NVH simulations. In this method, firstly the most influential parameters are determined using a SA to reduce the number of input parameters. Depending on the number of parameters and the computation time of the NVH simulation model, either the Morris SA or an EFAST SA is chosen. Finally, a fuzzy UA is performed, which quantifies the uncertainty of the output of the NVH simulation and provides its possible ranges. The procedure is applied to the NVH model for predicting air borne sound of an electric drive with 53 uncertain input parameters.

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Numerical Transfer Path Analysis for NVH System-Simulation Models

Pasch

Jacobs

Berroth

2021

IOP Conf. Ser.: Mater. Sci. Eng.

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For the assessment of the Noise, Vibration and Harshness (NVH) behavior of complex systems in early phases of the development process, validated modelling methods are available that allow the prediction of structure-borne and airborne noise at system level. However, due to large model sizes, the identification of weak spots in the vibroacoustic transfer behavior and the derivation of optimization measures are highly complex, time-consuming, and mostly not practical. In the field of experimental NVH analysis, transfer path analysis (TPA) has been established as target-oriented methods for identifying vibroacoustic anomalies at system level. In this contribution, TPA methods from the field of measurement technology are selected and applied to numerical NVH system models, aiming for high accuracy and low computational effort in post-processing. The applications of the methods are shown and discussed using an elastic multi-body simulation model of a tractor drivetrain with a transient run-up of the vehicle speed as an example. The classical direct-force and component-based blocked-force TPA methods selected and adapted for this study allow for efficient calculation of the sound contributions of numerical models. At the same time, they overcome typical challenges of experimental TPA, such as exact force determination or consideration of rotational degrees of freedom. In addition, the comparison of the two methods shows that the path contributions are in general different for classical and component-based TPA and only under specific conditions the same. Both numerical TPA methods allow for the identification of weak spots in the NVH behavior in an efficient and target-oriented way.

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Acoustic Optimization of a Power Take-off Gear Box Using Numerical Transfer Path Analysis

Cited by 3 publications

References 4 publications

Determining Dynamic Properties of Elastomer-Dampers by Means of Impact Testing

Determining Dynamic Properties of Elastomer-Dampers by Means of Impact Testing

Recheneffiziente Quantifizierung parametrischer Unsicherheiten in NVH-Systemsimulationsmodellen mittels Sensitivitäts- und Unsicherheitsanalyse

Numerical Transfer Path Analysis for NVH System-Simulation Models

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