Composite Loss Factors of Selected Laminated Beams

Blasingame, W.; DiTaranto, R. A.

doi:10.1121/1.1910037

Cited by 12 publications

(3 citation statements)

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“…5 The composite loss factors of laminated beams were obtained by DiTaranto and Blasingame. 6 The damping effectiveness of clamped-free and hinged-hinged tapered symmetric sandwich beams were studied by Rao and Stühler. 7 Asnani and Nakra studied the vibration damping characteristics and performed a forced vibration analysis of multi-layered beams with visco-elastic cores.…”

Section: Introductionmentioning

confidence: 99%

Static and Dynamic Stability Analysis of an Asymmetric Rotating Tapered Sandwich Beam Subjected to Pulsating Axial Load with Thermal Gradient

Pradhan¹,

Dash²

2019

The International Journal of Acoustics and Vibration

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The static and dynamic stability of an asymmetric rotating tapered sandwich beam subjected to pulsating axial load in temperature environment is studied under two different boundary conditions. The non-dimensional equations of motion and the boundary conditions are derived by applying Hamilton's energy principle. A coupled Hill's equations with complex coefficients are derived from the non-dimensional equations of motion by the application of the generalized Galerkin method. By the application of the Saito-Otomi conditions, zones of instabilities are obtained and presented graphically. For the calculation of the Young's module for the elastic layers, the effect of temperature has been taken in to consideration by means of a uniform thermal gradient along the longitudinal axes for both the upper and lower elastic layers. The effects of the taper parameter, core loss factor, thermal gradient, rotational speed, hub radius, and core density parameter on the static buckling loads and the regions of instability are investigated.

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Section: Introductionmentioning

confidence: 99%

Static and Dynamic Stability Analysis of an Asymmetric Rotating Tapered Sandwich Beam Subjected to Pulsating Axial Load with Thermal Gradient

Pradhan¹,

Dash²

2019

The International Journal of Acoustics and Vibration

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“…Among first studies of CLD treatments, Kerwin [1] developed a simplified theory to calculate the loss factor of a plate with CLD treatments. DiTaranto and Blasingame [2] extended Kerwin's work by accounting for the extensional deformations in the viscoelastic layer and obtained loss factors for three and five layer beams as a function of frequency. Mead and Markus [3] derived sixth-order equation of motion for beams in terms of transverse displacements.…”

Section: Introductionmentioning

confidence: 99%

Topology Optimization for Minimizing the Resonant Response of Plates with Constrained Layer Damping Treatment

Fang

Zheng

2015

Shock and Vibration

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A topology optimization method is proposed to minimize the resonant response of plates with constrained layer damping (CLD) treatment under specified broadband harmonic excitations. The topology optimization problem is formulated and the square of displacement resonant response in frequency domain at the specified point is considered as the objective function. Two sensitivity analysis methods are investigated and discussed. The derivative of modal damp ratio is not considered in the conventional sensitivity analysis method. An improved sensitivity analysis method considering the derivative of modal damp ratio is developed to improve the computational accuracy of the sensitivity. The evolutionary structural optimization (ESO) method is used to search the optimal layout of CLD material on plates. Numerical examples and experimental results show that the optimal layout of CLD treatment on the plate from the proposed topology optimization using the conventional sensitivity analysis or the improved sensitivity analysis can reduce the displacement resonant response. However, the optimization method using the improved sensitivity analysis can produce a higher modal damping ratio than that using the conventional sensitivity analysis and develop a smaller displacement resonant response.

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“…The theory is based on relating the shear strain of the damping layer to the transverse motion of the structure. DiTaranto and Blasingame [3] extended Kerwin's work by accounting for the extensional deformations in the visco-elastic layer and obtained composite loss factors for three and five layer beams as a function of frequency. DiTaranto [4] developed the sixth-order differential equations of motion for beams in terms of axial displacements.…”

Section: Introductionmentioning

confidence: 99%

Topology Optimization of Constrained Layer Damping on Plates Using Method of Moving Asymptote (MMA) Approach

Liu

Ronglu

Wang

et al. 2011

Shock and Vibration

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Damping treatments have been extensively used as a powerful means to damp out structural resonant vibrations. Usually, damping materials are fully covered on the surface of plates. The drawbacks of this conventional treatment are also obvious due to an added mass and excess material consumption. Therefore, it is not always economical and effective from an optimization design view. In this paper, a topology optimization approach is presented to maximize the modal damping ratio of the plate with constrained layer damping treatment. The governing equation of motion of the plate is derived on the basis of energy approach. A finite element model to describe dynamic performances of the plate is developed and used along with an optimization algorithm in order to determine the optimal topologies of constrained layer damping layout on the plate. The damping of visco-elastic layer is modeled by the complex modulus formula. Considering the vibration and energy dissipation mode of the plate with constrained layer damping treatment, damping material density and volume factor are considered as design variable and constraint respectively. Meantime, the modal damping ratio of the plate is assigned as the objective function in the topology optimization approach. The sensitivity of modal damping ratio to design variable is further derived and Method of Moving Asymptote (MMA) is adopted to search the optimized topologies of constrained layer damping layout on the plate. Numerical examples are used to demonstrate the effectiveness of the proposed topology optimization approach. The results show that vibration energy dissipation of the plates can be enhanced by the optimal constrained layer damping layout. This optimal technology can be further extended to vibration attenuation of sandwich cylindrical shells which constitute the major building block of many critical structures such as cabins of aircrafts, hulls of submarines and bodies of rockets and missiles as an invaluable design tool.

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Composite Loss Factors of Selected Laminated Beams

Cited by 12 publications

References 0 publications

Static and Dynamic Stability Analysis of an Asymmetric Rotating Tapered Sandwich Beam Subjected to Pulsating Axial Load with Thermal Gradient

Static and Dynamic Stability Analysis of an Asymmetric Rotating Tapered Sandwich Beam Subjected to Pulsating Axial Load with Thermal Gradient

Topology Optimization for Minimizing the Resonant Response of Plates with Constrained Layer Damping Treatment

Topology Optimization of Constrained Layer Damping on Plates Using Method of Moving Asymptote (MMA) Approach

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