Damping characteristics of flexural vibration for partially covered beams with constrained viscoelastic layers.

Dewa, Hiromi; Okada, Youji; Nagai, Bunshu

doi:10.1299/kikaic.55.1575

Cited by 5 publications

(4 citation statements)

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“…Zhou et al 18 assumed that the perforated parts did not have any materials in discontinuous damping structure, and investigated the effects of opening ratio on the loss factor. Dewa, et al 19 studied the vibration of discontinuous damping sandwich beam and found that the continuous damping treatment was not always more efficient than the discontinuous one. Zheng, et al 20 studied the effects of two damping patches with different length ratios as well as the spacing between the two patches on the damping performance.…”

Section: Introductionmentioning

confidence: 99%

Free vibration analysis of embedded and co-cured perforated damping sandwich composite beam

Long

Liang

2021

Journal of Composite Materials

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The free vibration behaviors of the embedded and co-cured perforated damping sandwich composite (ECPDSC) in which the holes are filled with resin are investigated. The displacement field of laminated structure and the equivalent elastic parameters of the heterogeneous damping layer are presented by the combination of the first order shear deformation theory with homogenization method. The dynamic equations of the structure are derived on basis of the equivalent complex modulus theory, and the theoretical results are verified by experimental platform. The relationships of damping area ratio and the thickness of damping layer as well as the elastic modulus of viscoelastic material with the dynamic properties of ECPDSC are theoretically explored further. Results indicate that the modal frequency decreases slowly when the damping area ratio is relatively small, the modal frequency decreases rapidly when the damping area ratio is relatively large, and the trend of loss factor is just opposite. This investigation will lay a foundation for the design and manufacture of composite components with light weight, large damping as well as high stiffness.

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Section: Introductionmentioning

confidence: 99%

Free vibration analysis of embedded and co-cured perforated damping sandwich composite beam

Long

Liang

2021

Journal of Composite Materials

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“…There are different types of transducers used for experimental studies to vibrate the specimen and to measure its response. For example, Dewa, et al [5] investigated the partial cover effect on simply supported beams using an electromagnetic exciter and eddy current type gas sensors as transducers, whilst Rao and Crocker [6] employed an impact hammer with an attached force transducer to excite the single lap joint configurations with the same end conditions, the response being measured by a mini-accelerometer. For the clamped-free end conditions, Park [7], and Douglas and Yang [8] used similar instrumentation to investigate the constrained layer treatment while Qian, et al [9] studied the same with plates.…”

Section: Introductionmentioning

confidence: 99%

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2020

Int J Astronaut Aeronautical Eng

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In designing polymer composites, while their basic mechanical properties are seen as the primary interest for safety concern, their inherent damping values are seen as the secondary for human being comfort, safety and health. However, in today's advanced aerial and land vehicles, comport and health of passengers are as important as their safety. The aim of this work is to investigate the dynamic and also quasi-static behaviors of a glass fibre-reinforced polymer matrix composite, Hexply 913/33%/UD280, to be considered for structural as well as vibratory conditions. The specimens with different angles of fibre orientations (0, ± 10°, ± 20°, ± 35°, ± 45°, ± 55°, ± 70°, ± 80° and 90°) were manufactured from the composite prepreg and subjected to a vibrating beam test with the clamped-free boundary conditions. Two different methods, the half power bandwidth and the logarithmic free decay, were used to measure the damping values to be able to compare the results. A universal testing machine was used to obtain the stress-strain behaviors of the specimens. It has been revealed that the specimens with the ± 20°, ± 35° and ± 45° fibre orientations are able to produce high damping values with reasonable high maximum stresses. Especially the one with the ± 45 orientation is seen the best as it provides a high damping value and high strains to failure with an acceptable high stress. It is believed that such specimens are suitable for structural, vibratory and also impacted conditions, which is desired by many designers.

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“…For experimental works, different types of transducer have been used in order to vibrate the specimen and to measure its response. Dewa et al [12] investigated the partial cover effect on simply supported beams using an electromagnetic exciter and eddycurrent-type gas sensors as transducers, whilst Rao and Crocker [13] employed an impact hammer with an attached force transducer to excite the single lap joint configurations with the same end conditions, the response being measured by a mini-accelerometer. For the clamped-free end conditions, Park [14] and Douglas and Yang [15] used similar instrumentation to investigate the constrained layer treatment while Qian et al [16] studied the same with plates.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Dynamic Properties of Composites in Vibration by Means of a Non-contact Mechanism

Kadıoğlu

2008

Journal of Reinforced Plastics and Composites

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When dynamic properties of structures in vibration are considered, their elastic modulus and damping properties are emphasized. One of the best ways for true measurement of damping is the use of a beam with free-free end conditions. The aim of this study is to investigate dynamic properties of composites by using the vibrating beam technique. The composite specimens with free-free end conditions were vibrated at their fundamental nodes. An electro-magnetic shaker was used to vibrate the specimens by means of air flow and their responses were taken by means of a microphone, a non-contact mechanism. It has been shown that this technique produces accurate and repeatable results and that this is a reliable method for the dynamic measurements.

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Damping characteristics of flexural vibration for partially covered beams with constrained viscoelastic layers.

Cited by 5 publications

References 0 publications

Free vibration analysis of embedded and co-cured perforated damping sandwich composite beam

Free vibration analysis of embedded and co-cured perforated damping sandwich composite beam

Untitled

Measurement of Dynamic Properties of Composites in Vibration by Means of a Non-contact Mechanism

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