P‐1.6: Scratch Behavior of Multilayer Flexible Panel Module

This study addresses the frequency–amplitude relationship of a nonlinear symmetric panel absorber mounted on a flexible wall. In many structural–acoustic works, only one flexible panel is considered in their models with symmetric configuration. There are very limited research investigations that focus on two flexible panels coupled with a cavity, particularly for nonlinear structural–acoustic problems. In practice, panel absorbers with symmetric configurations are common and usually mounted on a flexible wall. Thus, it should not be assumed that the wall is rigid. This study is the first work employing the weighted residual elliptic integral method for solving this problem, which involves the nonlinear multi-mode governing equations of two flexible panels coupled with a cavity. The reason for adopting the proposed solution method is that fewer nonlinear algebraic equations are generated. The results obtained from the proposed method and finite element method agree reasonably well with each other. The effects of some parameters such as vibration amplitude, cavity depth and thickness ratio, etc. are also investigated.

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Effect of filler content on scratch behavior and tribological performance of polyester/graphene oxide nanocomposite coating

Journal of Coatings Technology and Research ◽

10.1007/s11998-021-00489-7 ◽

2021 ◽

Author(s):

Nedia Gafsi ◽

Raquel Verdejo ◽

Mohamed Kharrat ◽

Massimiliano Barletta ◽

Miguel Ángel López-Manchado ◽

...

Keyword(s):

Graphene Oxide ◽

Filler Content ◽

Nanocomposite Coating ◽

Tribological Performance ◽

Scratch Behavior

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Simultaneous Measurement of Pressure and Velocity Fields of an Oblique SBLI on a Flexible Panel using PIV and PSP

AIAA AVIATION 2020 FORUM ◽

10.2514/6.2020-3001 ◽

2020 ◽

Author(s):

Santosh Vaibhav Varigonda ◽

Venkateswaran Narayanaswamy ◽

Isaac Boxx

Keyword(s):

Simultaneous Measurement ◽

Velocity Fields ◽

Flexible Panel

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Maximizing the efficiency of a flexible propulsor using experimental optimization

Journal of Fluid Mechanics ◽

10.1017/jfm.2015.35 ◽

2015 ◽

Vol 767 ◽

pp. 430-448 ◽

Cited By ~ 63

Author(s):

Daniel B. Quinn ◽

George V. Lauder ◽

Alexander J. Smits

Keyword(s):

Leading Edge ◽

The Body ◽

Phase Lag ◽

Force Measurements ◽

Experimental Optimization ◽

Image Velocimetry ◽

Flexible Panel ◽

Gradient Based ◽

Power Scale ◽

Effective Angle

AbstractExperimental gradient-based optimization is used to maximize the propulsive efficiency of a heaving and pitching flexible panel. Optimum and near-optimum conditions are studied via direct force measurements and particle image velocimetry (PIV). The net thrust and power scale predictably with the frequency and amplitude of the leading edge, but the efficiency shows a complex multimodal response. Optimum pitch and heave motions are found to produce nearly twice the efficiencies of optimum heave-only motions. Efficiency is globally optimized when (i) the Strouhal number is within an optimal range that varies weakly with amplitude and boundary conditions; (ii) the panel is actuated at a resonant frequency of the fluid–panel system; (iii) heave amplitude is tuned such that trailing-edge amplitude is maximized while the flow along the body remains attached; and (iv) the maximum pitch angle and phase lag are chosen so that the effective angle of attack is minimized. The multi-dimensionality and multi-modality of the efficiency response demonstrate that experimental optimization is well-suited for the design of flexible underwater propulsors.

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Scratch behavior and mechanical properties of alternating multi-layered PMMA/PC materials

Wear ◽

10.1016/j.wear.2021.204069 ◽

2021 ◽

pp. 204069

Author(s):

Yang Xu ◽

Jingxian Qin ◽

Jiabin Shen ◽

Shaoyun Guo ◽

Khalid Lamnawar

Keyword(s):

Mechanical Properties ◽

Scratch Behavior

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Modeling and Eigenfrequency Analysis of Sound-Structure Interaction in a Rectangular Enclosure with Finite Element Method

Advances in Acoustics and Vibration ◽

10.1155/2009/371297 ◽

2009 ◽

Vol 2009 ◽

pp. 1-9 ◽

Cited By ~ 9

Author(s):

Samira Mohamady ◽

Raja Kamil Raja Ahmad ◽

Allahyar Montazeri ◽

Rizal Zahari ◽

Nawal Aswan Abdul Jalil

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Natural Frequencies ◽

Active Noise Control ◽

Interior Noise ◽

Rectangular Enclosure ◽

Sound Structure ◽

Flexible Panel ◽

Experimental Works ◽

Element Method

Vibration of structures due to external sound is one of the main causes of interior noise in cavities like automobile, aircraft, and rotorcraft, which disturb the comfort of passengers. Accurate modelling of such phenomena is required in eigenfrequency analysis and in designing an active noise control system to reduce the interior noise. In this paper, the effect of periodic noise travelling into a rectangular enclosure is investigated with finite element method (FEM) using COMSOL Multiphysics software. The periodic acoustic wave is generated by a point source outside the enclosure and propagated through the enclosure wall and excites an aluminium flexible panel clamped onto the enclosure. The behaviour of the transmission of sound into the cavity is investigated by computing the modal characteristics and the natural frequencies of the cavity. The simulation results are compared with previous analytical and experimental works for validation and an acceptable match between them were obtained.

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