Browsing Research Articles, Department of Mechanical Engineering by Title
Now showing items 1-20 of 164
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A computational model for biosonar echoes from foliage
(PLOS, 2017-08-17)Since many bat species thrive in densely vegetated habitats, echoes from foliage are likely to be of prime importance to the animals’ sensory ecology, be it as clutter that masks prey echoes or as sources of information ... -
Acoustic Effects Accurately Predict an Extreme Case of Biological Morphology
(American Physical Society, 2009-07-17)The biosonar system of bats utilizes physical baffle shapes around the sites of ultrasound emission for diffraction-based beam forming. Among these shapes, some extreme cases have evolved that include a long noseleaf ... -
Acoustic performance of a stretched membrane and porous blanket combination
(Acoustical Society of America, 1976)The sound absorption performance of an acoustic absorber consisting of a stretched circular membrane placed a short distance in front of a fiberglass blanket was both measured and predicted. Both theoretical and experimental ... -
Acoustics 1991: Active structural acoustic control
(Acoustical Society of America, 1992-01-01)In summary, the ASAC technique has demonstrated much potential in aerospace and marine applications. Future work will center on extending these techniques to broadband disturbances, more complex structures and improved ... -
Active control of coupled wave propagation in fluid-filled elastic cylindrical shells
(Acoustical Society of America, 1993-09-01)A control approach to reduce the total power propagating along fluid-filled elastic cylinders is analytically investigated. The motion of the cylinder is described by the Kennard shell equations fully coupled to the interior ... -
Active control of far-field sound radiated by a rectangular panel - a general analysis
(Acoustical Society of America, 1992-04-01)In this paper a general analysis is presented for the active control of the far-field harmonic sound radiated by a rectangular panel that is built into an infinite baffle. In this analysis, the panel vibration may be ... -
Active control of noise transmission through rectangular plates using multiple piezoelectric or point force actuators
(Acoustical Society of America, 1991-11-01)This paper analytically demonstrates the use of multiple piezoelectric actuators bonded to the surface and point force actuators applied directly to a plate to reduce sound transmission through the plate. A harmonic plane ... -
Active control of sound radiation due to subsonic wave scattering from discontinuities on fluid-loaded plates. I: Far-field pressure
(Acoustical Society of America, 1991-10-01)Active control of sound radiation due to subsonic wave scattering from discontinuities represented by a line constraint or by a uniform reinforcing rib positioned on a fluid-loaded infinite plate is analytically studied. ... -
Active control of sound radiation from a fluid-loaded rectangular uniform plate
(Acoustical Society of America, 1993-01-01)Active control of sound radiation from a simply supported rectangular fluid-loaded plate is analytically studied. The plate is assumed to be excited by a point force at subsonic frequencies. The solution to the plate motion ... -
Active control of sound radiation from a plate using a polyvinylidene fluoride volume displacement sensor
(Acoustical Society of America, 1998-03-01)This paper presents a new volume displacement sensor (made of shaped strips of PVDF film) and the experimental implementation of this sensor in an active control system. A design strategy for a PVDF sensor detecting the ... -
Active control of sound radiation from a simply supported beam: Influence of bending near-field waves
(Acoustical Society of America, 1993-05-01)Active control of sound radiation from a baffled simply supported finite beam is analytically studied. The beam is subjected to a harmonic input force and the resulting acoustic field is minimized by applying a control ... -
Active isolation of vibration with adaptive structures
(Acoustical Society of America, 1994-07-01)The problem of actively isolating the periodic vibrations of a rigid machine mounted on a supporting flexible structure is usually approached by applying the active inputs in parallel or series with the passive inputs. ... -
Adaptive feedforward and feedback methods for active/passive sound radiation control using smart foam
(Acoustical Society of America, 1998-07-01)This work investigates and compares the potential of adaptive feed forward and feedback methods for a hybrid active/passive radiation control using smart foam. The radiating structure is a vibrating plate mounted in a rigid ... -
Adaptive near-field beamforming techniques for sound source imaging
(Acoustical Society of America, 2009-02-01)Phased array signal processing techniques such as beamforming have a long history in applications such as sonar for detection and localization of far-field sound sources. Two sometimes competing challenges arise in any ... -
Advanced time domain wave-number sensing for structural acoustic systems. I. Theory and design
(Acoustical Society of America, 1994-06-01)This paper discusses new work concerned with developing structural sensors and associated signal processing techniques that provide time domain estimates of far-field pressure or structural wave-number information. The ... -
Advanced time domain wave-number sensing for structural acoustic systems. II. Active radiation control of a simply supported beam
(Acoustical Society of America, 1994-06-01)A real time structural acoustic sensor and associated signal processing is developed and applied to the active control of sound radiated by a simply supported beam. The sensor consists of multiple accelerometers mounted ... -
Advanced time domain wave-number sensing for structural acoustic systems. Part III. Experiments on active broadband radiation control of a simply supported plate
(Acoustical Society of America, 1995-11-01)The present work gives further developments and experimental testing of a new time domain structural sensing technique for predicting wave-number information and acoustic radiation from vibrating structures. Most structure-borne ... -
Alternating and direct current field effects on the structure-property relationships in Na0.5Bi0.5TiO3-x% BaTiO3 textured ceramics
(AIP Publishing, 2013-06-01)The influence of alternating (ac) and direct current (dc) fields on the structural and dielectric properties of [001](PC) textured Na0.5Bi0.5TiO3-7%BaTiO3 (NBT-7%BT) ceramics has been investigated. X-ray diffraction ... -
Analytical investigation of active control of radiated inlet fan noise
(Acoustical Society of America, 1996-01-01)An analytical mode has been de loped to study the potential of active noise control techniques for Ie reducing radiated tonal inlet noise from turbofan engines. The analytical model consists of multiple control sources ... -
Application of Recursive Least Square Algorithm on Estimation of Vehicle Sideslip Angle and Road Friction
(Hindawi Publishing Corporation, 2010)A recursive least square (RLS) algorithm for estimation of vehicle sideslip angle and road friction coefficient is proposed. The algorithm uses the information from sensors onboard vehicle and control inputs from the control ...
