Computational and experimental studies of microvascular void features for passive-adaptation of structural panel dynamic properties
TL;DR: In this article, the authors explored an idea of adapting the static and dynamic material distribution of panels through embedded microvascular channels and strategically placed voids that permit the internal movement of fluids within the panels for structural dynamic control.
About: This article is published in Journal of Sound and Vibration.The article was published on 2018-01-06. It has received 3 citations till now. The article focuses on the topics: Structural system.
Citations
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TL;DR: In this article, a fractional order derivative viscoelastic model is used for the analysis of the dispersion characteristics of the velocity wave in a FGM hollow cylinder with material changing in the thickness direction, where the Weyl definition of fractional orders and extended Legendre polynomial approach are employed for the derivations of the governing equations.
49 citations
TL;DR: In this paper, a multistage high pressure compressor was investigated and it was confirmed that the acoustic resonance frequency and its side band frequencies are generated by modulation of a rotating noise source at the rotor speed which is the excitation source of rotor blades vibration.
11 citations
TL;DR: In this article, a physical model for acoustic resonance in the annular cavity structure is developed to represent the typical characteristic when acoustic resonance occurs in a multistage high pressure compressor.
5 citations
References
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TL;DR: A self-healing system capable of autonomously repairing repeated damage events via a three-dimensional microvascular network embedded in the substrate is reported, opening new avenues for continuous delivery of healing agents for self-repair as well as other active species for additional functionality.
Abstract: Self-healing polymers composed of microencapsulated healing agents exhibit remarkable mechanical performance and regenerative ability, but are limited to autonomic repair of a single damage event in a given location. Self-healing is triggered by crack-induced rupture of the embedded capsules; thus, once a localized region is depleted of healing agent, further repair is precluded. Re-mendable polymers can achieve multiple healing cycles, but require external intervention in the form of heat treatment and applied pressure. Here, we report a self-healing system capable of autonomously repairing repeated damage events. Our bio-inspired coating-substrate design delivers healing agent to cracks in a polymer coating via a three-dimensional microvascular network embedded in the substrate. Crack damage in the epoxy coating is healed repeatedly. This approach opens new avenues for continuous delivery of healing agents for self-repair as well as other active species for additional functionality.
1,415 citations
TL;DR: In this article, an active vibration damper for a cantilever beam was designed using a distributed-parameter actuator and distributedparameter control theory, and preliminary testing of the damper was performed on the first mode of the beam.
Abstract: An active vibration damper for a cantilever beam was designed using a distributed-parameter actuator and distributed-parameter control theory. The distributed-parameter actuator was a piezoelectric polymer, poly (vinylidene fluoride). Lyapunov's second method for distributed-parameter systems was used to design a control algorithm for the damper. If the angular velocity of the tip of the beam is known, all modes of the beam can be controlled simultaneously. Preliminary testing of the damper was performed on the first mode of the cantilever beam. A linear constant-gain controller and a nonlinear constant-amplitude controller were compared. The baseline loss factor of the first mode was 0.003 for large-amplitude vibrations (± 2 cm tip displacement) decreasing to 0.001 for small vibrations (±0.5 mm tip displacement). The constant-gain controller provided more than a factor of two increase in the modal damping with a feedback voltage limit of 200 V rms. With the same voltage limit, the constant-amplitude controller achieved the same damping as the constant-gain controller for large vibrations, but increased the modal loss factor by more than an order of magnitude to at least 0.040 for small vibration levels.
1,408 citations
"Computational and experimental stud..." refers background in this paper
...For panels, the multi-dimensional modal vibrations signify that internal void placement obtains an increased importance when compared to the lower dimensionality of cantilever beams [7,16,18]....
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TL;DR: Of particular interest is the ability of microvascular networks to beoenable repetitive healing of damage in biological and synthetics systems, for example, human skin can undergo repeated repairof damage in a single location.
Abstract: have been employedto create planar and 3D microvascular networks. However, todate, simple networks composed of single, uniform vascularpathways have mainly been constructed.Ofparticularinterestistheabilityofmicrovascularnetworkstoenable repetitive healing of damage in biological and syntheticsystems. For example, human skin can undergo repeated repairof damage in a single location (Fig. 1a). The outer layer of skin(the epidermis) serves as a protective coating, preventing outsidepathogens from infiltrating the body.
368 citations
TL;DR: In this article, the authors used the theory proposed by Biot to calculate the transmission loss of double panels at arbitrary angles of incidence; results calculated over a range of incidence angles may then be combined to yield the random incidence transmission loss.
272 citations
TL;DR: In this article, an analytical and experimental investigation of active control of sound transmission through double panel systems has been performed, where the control inputs, in the form of piezoelectric actuators, were applied to the structure while the radiating pressure field was minimized.
138 citations
"Computational and experimental stud..." refers methods in this paper
...In addition, the reduction of vibration or acoustic energy transmission through panels has been achieved using piezoceramic actuator transducers [10], variable stiffness panels with piezoelectric control actuators [11,12], sensoriactuators that are used in contrast to control units composed of separate sensors and actuators [13], control systems that are aided with the use of ribstiffened panels [14], and shunted piezoelectric patch absorbers [15]....
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