Prof. Ajit K. Mal Profile

Prof. Ajit K. Mal

Distinguished Professor at UCLA

SPIE Involvement:

Author

Publications (35)

Proceedings Article | 22 March 2021 Presentation + Paper

Inverse fuzzy arithmetic for material characterization of composites using guided waves

Leonardo Araque, Lifu Wang, Ajit Mal, Christoph Schaal

Proceedings Volume 11593, 115930U (2021) https://doi.org/10.1117/12.2583947

KEYWORDS: Composites, Waveguides, Ultrasonics, Material characterization, Fuzzy logic, Data modeling, Velocity measurements, Uncertainty analysis, Optimization (mathematics), Nondestructive evaluation

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Proceedings Article | 6 May 2020 Paper

Numerical and experimental investigation of damage detection in stiffened composite panels using guided ultrasonic waves

Steffen Tai, Fumika Kotobuki, Ajit Mal, Christoph Schaal

Proceedings Volume 11381, 1138102 (2020) https://doi.org/10.1117/12.2558845

KEYWORDS: Composites, Waveguides, Wave propagation, Scattering, Transducers, Ultrasonics, Damage detection, Wave plates, Nondestructive evaluation

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Proceedings Article | 24 April 2020 Presentation

Frequency conversion through nonlinear mixing in acoustic waves (Conference Presentation)

Joseph Schneider, Ting Lu, Sidhant Tiwari, Xiating Zou, Ajit Mal, Robert Candler, Yuanxun Wang, Greg Carman

Proceedings Volume 11379, 113792I (2020) https://doi.org/10.1117/12.2558673

KEYWORDS: Aluminum nitride, Capacitance, Motion models, Inductance, Electronics, Acoustics, Silicon, Platinum, Circuit switching, Resistance

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Proceedings Article | 23 April 2020 Paper

Uncertainty characterization of guided ultrasonic wave properties in composite materials

Leonardo Araque, Lifu Wang, Steffen Tai, Ajit Mal, Christoph Schaal

Proceedings Volume 11381, 113810J (2020) https://doi.org/10.1117/12.2558853

KEYWORDS: Dispersion, Fuzzy logic, Composites, Wave propagation, Waveguides, Ultrasonics, Material characterization, Systems modeling, Mechanics, Stochastic processes

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Proceedings Article | 5 April 2017 Presentation + Paper

Laser Doppler velocimetry and PZT sensing for the study of guided waves in a stepped aluminum plate

L. Maio, F. Ricci, V. Memmolo, N. D. Boffa, E. Monaco, A. Mal, C. Schaal

Proceedings Volume 10170, 101701S (2017) https://doi.org/10.1117/12.2260140

KEYWORDS: Wave propagation, Doppler effect, Wave plates, Nondestructive evaluation, Velocity measurements, Vibrometry, Waveguides, Aluminum, Actuators, Laser Doppler velocimetry, Transducers, Dispersion

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Proceedings Article | 5 April 2017 Paper

On the assumption of transverse isotropy of a honeycomb sandwich panel for NDT applications

Christoph Schaal, Steffen Tai, Ajit Mal

Proceedings Volume 10170, 1017022 (2017) https://doi.org/10.1117/12.2260092

KEYWORDS: Nondestructive evaluation, Composites, Ultrasonics, Aircraft structures, Waveguides, Defect detection, Wave propagation, 3D modeling, Dispersion, Phase velocity, Lawrencium

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Proceedings Article | 5 April 2017 Paper

Parametric studies for semi-analytical investigation of plate-mounted resonators

Christoph Schaal, Robert M'Closkey, Ajit Mal

Proceedings Volume 10170, 101700O (2017) https://doi.org/10.1117/12.2262002

KEYWORDS: Wave propagation, Resonators, Modal analysis, Microresonators, Finite element methods, Microelectromechanical systems, Sensors, Motion models, Wave plates, Solids, Ultrasonics, Chemical elements, Gyroscopes, Superposition, Dispersion

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Proceedings Article | 23 March 2015 Paper

Guided waves for detection of delamination and disbonding in stiffened composite panels

Fabrizio Ricci, Ernesto Monaco, Leonardo Lecce, Ajit Mal

Proceedings Volume 9438, 94380P (2015) https://doi.org/10.1117/12.2084382

KEYWORDS: Composites, Waveguides, Wave propagation, Ferroelectric materials, Receivers, Ultrasonics, Wave plates, Transducers, Signal detection, Sensors

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Proceedings Article | 23 March 2015 Paper

Dispersion of guided waves in composite laminates and sandwich panels

Christoph Schaal, Ajit Mal

Proceedings Volume 9438, 94380L (2015) https://doi.org/10.1117/12.2083870

KEYWORDS: Waveguides, Composites, Wave propagation, Dispersion, Aluminum, Skin, Phase velocity, Ultrasonics, Transducers, Nondestructive evaluation

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Proceedings Article | 17 April 2013 Paper

NDE of composite structures using ultrasonic guided waves

Ajit Mal, Fabrizio Ricci, Himadri Samajder, Harsh Baid

Proceedings Volume 8695, 86950E (2013) https://doi.org/10.1117/12.2009845

KEYWORDS: Composites, Waveguides, Aluminum, Receivers, Wave propagation, Ultrasonics, Nondestructive evaluation, Transducers, Skin, Aerospace engineering

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Proceedings Article | 17 April 2013 Paper

Lamb waves in a honeycomb composite sandwich plate

Himadri Samajder, Harsh Baid, Fabrizio Ricci, Ajit Mal

Proceedings Volume 8695, 869505 (2013) https://doi.org/10.1117/12.2010087

KEYWORDS: Composites, Aluminum, Waveguides, Transducers, Dispersion, Wave propagation, Wave plates, Ultrasonics, Receivers, Aerospace engineering

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Proceedings Article | 6 May 2009 Paper

Propogation loss with frequency of ultrasound guided waves in a composite metal-honeycomb structure

Indu Saxena, Harsh Baid, Narciso Guzman, Lothar Kempen, Ajit Mal

Proceedings Volume 7314, 73140P (2009) https://doi.org/10.1117/12.835473

KEYWORDS: Ferroelectric materials, Ultrasonography, Waveguides, Fiber Bragg gratings, Composites, Receivers, Signal attenuation, Aerospace engineering, Wave propagation, Diagnostics

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Proceedings Article | 8 April 2009 Paper

Dynamic based damage detection in composite structures

Sauvik Banerjee, Fabrizio Ricci, Harsh Baid, Ajit Mal

Proceedings Volume 7295, 72950H (2009) https://doi.org/10.1117/12.816214

KEYWORDS: Composites, Wave propagation, Aerospace engineering, Damage detection, Sensors, Receivers, Actuators, Ultrasonics, Defect detection, Aluminum

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Proceedings Article | 21 April 2008 Paper

Detection of disbonds in a honeycomb composite structure using guided waves

Harsh Baid, Sauvik Banerjee, Shiv Joshi, Siddhartha Mal

Proceedings Volume 6935, 693504 (2008) https://doi.org/10.1117/12.776349

KEYWORDS: Composites, Waveguides, Skin, Transducers, Aerospace engineering, Ultrasonics, Aircraft structures, Ultrasonography, Wave plates, Receivers

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Proceedings Article | 11 April 2007 Paper

Autonomous health monitoring of composite structures using a statistical damage index approach

Sauvik Banerjee, Fabrizio Ricci, Ajit Mal

Proceedings Volume 6532, 65321U (2007) https://doi.org/10.1117/12.719626

KEYWORDS: Sensors, Actuators, Composites, Wave propagation, Structural health monitoring, Ultrasonics, Reliability, Transducers, Statistical analysis, Data acquisition

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Proceedings Article | 28 March 2006 Paper

Measurement of thin film interfacial properties using nanosecond laser source

Ajit Mal, Sauvik Banerjee, Vijay Gupta

Proceedings Volume 6177, 61770Y (2006) https://doi.org/10.1117/12.660429

KEYWORDS: Interfaces, Wave propagation, Laser sources, Thin films, Reflection, Titanium, Tissues, Aluminum, Nd:YAG lasers, Multilayers

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Proceedings Article | 15 March 2006 Paper

Autonomous health monitoring of a stiffened composite plate

Ajit Mal, Sauvik Banerjee, Fabrizio Ricci, Ernesto Monaco, L. Lecce

Proceedings Volume 6177, 617701 (2006) https://doi.org/10.1117/12.660424

KEYWORDS: Composites, Sensors, Wave propagation, Transducers, Actuators, Ultrasonics, Statistical analysis, Receivers, Wave plates, Structural health monitoring

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Proceedings Article | 9 May 2005 Paper

An analytical model for the interaction of focused ultrasound with biological structures

Ajit Mal, Feng Feng

Proceedings Volume 5768, (2005) https://doi.org/10.1117/12.600576

KEYWORDS: Ultrasonography, Testing and analysis, Interfaces, Tissues, Thermal effects, Finite element methods, Biological research, Spherical lenses, Acoustics, Wave propagation

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Proceedings Article | 9 May 2005 Paper

Impact damage detection in composite structures using Lamb waves

Ajit Mal, Frank Shih, Fabrizio Ricci, Sauvik Banerjee

Proceedings Volume 5768, (2005) https://doi.org/10.1117/12.600566

KEYWORDS: Composites, Acoustic emission, Transducers, Damage detection, Wave propagation, Sensors, Wave plates, Ultrasonics, Epoxies, Nondestructive evaluation

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Proceedings Article | 21 July 2004 Paper

Guided acoustic emission waves in a thick composite plate

Ajit Mal, Sauvik Banerjee

Proceedings Volume 5394, (2004) https://doi.org/10.1117/12.543818

KEYWORDS: Composites, Lead, Wave propagation, Acoustic emission, Wave plates, Waveguides, Interfaces, Transducers, Multilayers, Nondestructive evaluation

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Proceedings Article | 21 July 2004 Paper

Automated structural health monitoring system using acoustic emission and modal data

Ajit Mal, Sauvik Banerjee, Fabrizio Ricci

Proceedings Volume 5394, (2004) https://doi.org/10.1117/12.539194

KEYWORDS: Composites, Wave propagation, Sensors, Structural health monitoring, Receivers, Aluminum, Acoustic emission, Ultrasonics, Wave plates, Inspection

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Proceedings Article | 1 August 2003 Paper

Damage detection in structures from vibration and wave propagation data

Ajit Mal, Fabrizio Ricci, Steve Gibson, Sauvik Banerjee

Proceedings Volume 5047, (2003) https://doi.org/10.1117/12.484449

KEYWORDS: Data modeling, Systems modeling, Wave propagation, System identification, Sensors, Databases, Damage detection, Aerospace engineering, Matrices, Structural health monitoring

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Proceedings Article | 1 August 2003 Paper

Acoustic emission waveforms in composite laminates under low velocity impact

Ajit Mal, Frank Shih, Sauvik Banerjee

Proceedings Volume 5047, (2003) https://doi.org/10.1117/12.484448

KEYWORDS: Acoustic emission, Composites, Transducers, Acoustics, Wavelet transforms, Wave plates, Data acquisition, Ultrasonics, Sensors, Aerospace engineering

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Proceedings Article | 1 August 2003 Paper

Ultrasonic lamb waves in a thin plate

Ajit Mal, Sauvik Banerjee, William Prosser

Proceedings Volume 5047, (2003) https://doi.org/10.1117/12.484450

KEYWORDS: Composites, Wave plates, Wave propagation, Aluminum, Finite element methods, Ultrasonics, Waveguides, Fourier transforms, Aerospace engineering, Epoxies

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Proceedings Article | 1 August 2003 Paper

Pressure and temperature distribution in biological tissues by focused ultrasound

Ajit Mal, Feng Feng, Michael Kabo, Jeffrey Wang, Yoseph Bar-Cohen

Proceedings Volume 5047, (2003) https://doi.org/10.1117/12.484447

KEYWORDS: Ultrasonography, Tissues, Bone, Thermal effects, Finite element methods, Computed tomography, Spherical lenses, Acoustics, Transducers, Interfaces

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Proceedings Article | 11 June 2002 Paper

Ultrasonic waves in an open cell foam

Ajit Mal, Sauvik Banerjee, Darren Rogers

Proceedings Volume 4702, (2002) https://doi.org/10.1117/12.469901

KEYWORDS: Foam, Ultrasonics, Wave propagation, X-rays, Carbon, Data modeling, Manufacturing, Particles, Aerospace engineering, Nondestructive evaluation

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Proceedings Article | 11 June 2002 Paper

Interaction of focused ultrasound with biological materials

Ajit Mal, Feng Feng, Michael Kabo, Jeffrey Wang, Yoseph Bar-Cohen

Proceedings Volume 4702, (2002) https://doi.org/10.1117/12.469894

KEYWORDS: Ultrasonography, Finite element methods, Solids, Thermal effects, Tissues, Interfaces, Aluminum, Acoustics, Bone, Cavitation

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Proceedings Article | 24 July 2001 Paper

Nondestructive characterization of the properties of thin diaphragms

Ajit Mal, D. Zheng, K. Tu, X. Wang, Y. Korkmaz

Proceedings Volume 4335, (2001) https://doi.org/10.1117/12.434175

KEYWORDS: Silicon, Thin films, Etching, Nondestructive evaluation, Composites, Oxides, Microelectronics, Data centers, Interferometers, Semiconducting wafers

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Proceedings Article | 28 January 1999 Paper

Composite materials stiffness determination and defects characterization using enhanced leaky Lamb wave dispersion data acquisition method

Yoseph Bar-Cohen, Ajit Mal, Shyh-Shiuh Lih, Zensheu Chang

Proceedings Volume 3586, (1999) https://doi.org/10.1117/12.339892

KEYWORDS: Composites, Data acquisition, Nondestructive evaluation, Wave plates, Dispersion, Reflection, Data processing, Ultrasonics, Scanners, Inspection

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Proceedings Article | 28 January 1999 Paper

NDE of hidden flaws in aging aircraft structures using obliquely backscattered ultrasonic signals (OBUS)

Yoseph Bar-Cohen, Ajit Mal, Marvin Lasser

Proceedings Volume 3586, (1999) https://doi.org/10.1117/12.339903

KEYWORDS: Corrosion, Nondestructive evaluation, Ultrasonics, Aircraft structures, Metals, Inspection, Aluminum, Real time imaging, Imaging systems, Backscatter

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Proceedings Article | 31 March 1998 Paper

Composite material defect characterization using leaky Lamb wave dispersion data

Yoseph Bar-Cohen, Ajit Mal, Zensheu Chang

Proceedings Volume 3396, (1998) https://doi.org/10.1117/12.301519

KEYWORDS: Composites, Nondestructive evaluation, Data acquisition, Dispersion, Data modeling, Scanners, Heat treatments, Wave plates, Reflection, Ultrasonics

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Proceedings Article | 31 March 1998 Paper

Perturbation solution for the interaction of Lamb waves with localized surface defects

Anter El-Azab, Ajit Mal

Proceedings Volume 3397, (1998) https://doi.org/10.1117/12.305038

KEYWORDS: Wave plates, Reflection, Corrosion, Superposition, Scattering, Waveguides, Fourier transforms, Radium, Aerospace engineering, Inspection

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Proceedings Article | 31 March 1998 Paper

NDE of rivet holes in aging aircraft components using Lamb waves

Ajit Mal, Zensheu Chang

Proceedings Volume 3397, (1998) https://doi.org/10.1117/12.305037

KEYWORDS: Waveguides, Transducers, Nondestructive evaluation, Wave plates, Wave propagation, Corrosion, Inspection, Finite element methods, Phase velocity, Defect detection

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Proceedings Article | 15 November 1996 Paper

Measurement of thickness and elastic properties of electroactive polymer films using plate wave dispersion data

Yoseph Bar-Cohen, Shyh-Shiuh Lih, Anter El-Azab, Ajit Mal

Proceedings Volume 2948, (1996) https://doi.org/10.1117/12.259187

KEYWORDS: Wave plates, Polymers, Thin films, Polymer thin films, Electroactive polymers, Dispersion, Reflection, Transducers, Algorithms, Aerospace engineering

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