Representation of Constrained/Unconstrained Layer Damping Treatments in FEA/SEA Vehicle System Models: A Simplified Approach

Akanda, Anab; Goetchius, Gregory M.

doi:10.4271/1999-01-1680

Cited by 14 publications

(4 citation statements)

References 7 publications

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“…RKU method, named after its developers Ross, Kerwin and Ungar, is the most commonly used method for characterizing the behaviour of three-layer damping treatments [1]. This method uses a fourth order differential equation for a uniform beam with the sandwich construction of the 3-layer laminate system represented as an equivalent complex stiffness.…”

Section: Fea Modelmentioning

confidence: 99%

CAE Model Correlation & Design Optimization of a Laminated Steel Oil Pan by means of Acceleration and Strain Measurement on a Fired Engine

YANAROCAK¹,

ÇEKİÇ²

2015

International Journal of Engineering Technologies IJET

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In this paper, a simultaneous design and development work for a diesel engine oil pan is presented. The interesting point making the design of the oil pan so special is its laminated steel material. Beside its material, due to the deep-drawing production method, to determine the natural frequencies of the structure with Computer Aided Engineering (CAE) methodology is a problem for the design engineer. Especially when the highly nonlinear character of the oil pan and regions at different thicknesses sum up with the hardness of liquid modelling, free vibration modal analysis of the design at virtual environment becomes extremely challenging. Therefore, instead of refining the material characteristics in virtual design, first a primary 3D dummy design is generated. Afterwards, a production method and material intent sample is produced with soft tool. Hammer test is applied on this sample filled with oil, therefore modal shapes and frequencies are gained. As a result, CAE modal analysis is generated and correlated by hammer test results; hence the first challenge of modelling the liquid is overcome. Then, critical stress locations are determined with the CAE durability analysis. After instrumenting the pan with optimum number of accelerometers and strain-gages from these critical locations, a durability test on a fired engine is run. With the measurements here, the CAE durability analysis is refined so the second challenge of material nonlinearity and thinning due to the deep-drawing method is also overcome. Lastly, with the CAE durability simulation, a secondary 3D design proposal is established. Normally the method reach to success here, but to validate it, a secondary sample is produced, instrumented again with accelerometers & gages and tested resulting in significant improvement in terms of durability. With this approach, a method to perform a fail-safe oil pan design in single loop is verified.

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Section: Fea Modelmentioning

confidence: 99%

CAE Model Correlation & Design Optimization of a Laminated Steel Oil Pan by means of Acceleration and Strain Measurement on a Fired Engine

YANAROCAK¹,

ÇEKİÇ²

2015

International Journal of Engineering Technologies IJET

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“…Various, well documented approaches have been developed to simulate damping materials. 2 In this study, the RKU method is used to simulate damping treatment, 2 which, despite its simplicity, works well for both constrained and unconstrained damping treatment. In this method, equivalent properties of damping treatments with base layers are estimated and assigned at the element level.…”

Section: Perform Modal Analysis and Extract Modal Strain Energy Upmentioning

confidence: 99%

Optimization of Damping Treatment for Structure Borne Noise Reduction

Subramanian¹,

Surampudi²,

Thomson³

et al. 2003

SAE Technical Paper Series

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“…In one modelling approach, the theoretical RUK model is used with the single-layer method to construct a discretized single-layer-element that simultaneously represents all of the layers. Akanda et al [4] used NASTRAN to set up a single-layer-element FEM shell element model of an automobile part. In that work, a subroutine was developed that would calculate the effective bending stiffness of a composite beam by using the equations from the RUK model.…”

Section: Introductionmentioning

confidence: 99%

Design Optimization for Vibration Reduction of Viscoelastic Damped Structures Using Genetic Algorithms

Xie

Shepard

Woodbury

2009

Shock and Vibration

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Due to the large number of design variables that can be present in complex systems incorporating visco-elastic damping, this work examines the application of genetic algorithms in optimizing the response of these structures. To demonstrate the applicability of genetic algorithms (GAs), the approach is applied to a simple viscoelastically damped constrained-layer beam. To that end, a finite element model (FEM) derived by Zapfe, which was based on Rao's formulation, was used for a beam with constrained-layer damping. Then, a genetic algorithm is applied to simultaneously determine the thicknesses of the viscoelastic damping layer and the constraining layer that provide the best response. While the targeted response is ultimately at the discretion of the designer, a few different choices for the fitness function are shown along with their corresponding impact on the vibratory response. By integrating the FEM code within the GA routine, it is easier to include the frequency-dependence of both the shear modulus and the loss factors for the viscoelastic layer. Examples are provided to demonstrate the capabilities of the method. It is shown that while a multi-mode optimization target provides significant reductions, the response for that configuration is inferior to the response when only single-mode reduction is considered. The results also reveal that the optimum configuration has a lower response level than when a thick layer of damping material is used. By demonstrating the applicability of GA for a simple beam structure, the approach can be extended to more complex damped structures.

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Representation of Constrained/Unconstrained Layer Damping Treatments in FEA/SEA Vehicle System Models: A Simplified Approach

Cited by 14 publications

References 7 publications

CAE Model Correlation & Design Optimization of a Laminated Steel Oil Pan by means of Acceleration and Strain Measurement on a Fired Engine

CAE Model Correlation & Design Optimization of a Laminated Steel Oil Pan by means of Acceleration and Strain Measurement on a Fired Engine

Optimization of Damping Treatment for Structure Borne Noise Reduction

Design Optimization for Vibration Reduction of Viscoelastic Damped Structures Using Genetic Algorithms

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