Papers by Banibrata Poddar
Journal of the Acoustical Society of America, Sep 1, 2016
Acta Mechanica, Nov 23, 2019
Smart Materials and Structures, Nov 26, 2018
Journal of Nondestructive Evaluation, May 20, 2017
The goal of a structural health monitoring system is to implement processes to detect and charact... more The goal of a structural health monitoring system is to implement processes to detect and characterize damages in engineering structures. These systems may use many different physical phenomena to detect and characterize damages. One of these phenomena is elastic wave propagation in thin plate like structures, known as Lamb wave propagation. To develop a SHM (structural health monitoring) system based on Lamb wave propagation we first need to understand how Lamb waves interact with different damage types. The aim of this study is to develop an understanding of how Lamb waves interact with different types of damages using analytical modeling and FEM. The goal is to identify and characterize a surface breaking crack by understanding its effect on Lamb waves scattered from it. doi: 10.12783/SHM2015/75
Nondestructive Characterization and Monitoring of Advanced Materials, Aerospace, Civil Infrastructure, and Transportation XII, 2018
Structural health monitoring (SHM) and nondestructive evaluation (NDE) methods rely on the interp... more Structural health monitoring (SHM) and nondestructive evaluation (NDE) methods rely on the interpretation of ultrasonic signals. These ultrasonic signals may result from the passive capture of the acoustic emission (AE) waves emitted by a crack or from the waves scattered by the crack during an active interrogation of the structure. Current AE signal interpretation methods can identify AE events, count their rate of appearance, and even locate their location using multiple sensors and a triangulation method. To evaluate the crack size, an active SHM method is employed to relate the scatter signals with the crack size. No method to extract the crack size from the AE signals collected during passive SHM exists at the moment. In this paper, we suggest a novel approach aimed at connecting the crack length to certain signature features that may be identified in the AE signal. One of the main challenges of this approach is to develop a physics of materials based understanding of the gener...
Journal of Sound and Vibration, 2018
Journal of Nondestructive Evaluation, 2017
Nondestructive Characterization and Monitoring of Advanced Materials, Aerospace, and Civil Infrastructure 2016, 2016
Health Monitoring of Structural and Biological Systems 2017, 2017
Structural Health Monitoring, 2017
In this study, we focus on analyzing the acoustic emission waveforms of the fatigue crack growth ... more In this study, we focus on analyzing the acoustic emission waveforms of the fatigue crack growth despite the conventional statistics-based analysis of acoustic emission. The acoustic emission monitoring technique is a well-known approach in the non-destructive evaluation/structural health monitoring research field. The growth of the fatigue crack causes the acoustic emission in the material that propagates in the structure. The acoustic emission happens not only from the crack growth but also from the interaction of the crack tips during the fatigue loading in the structure. The acoustic emission waveforms are generated from the acoustic emission events; they propagate and create local vibration modes along the crack faces (crack resonance). In-situ fatigue and acoustic emission experiments were conducted to monitor the acoustic emission waveforms from the fatigue cracks. Several test specimens were used in the fatigue experiments, and corresponding acoustic emission waveforms were ...
The Journal of the Acoustical Society of America, 2016
This paper presents an inexpensive but accurate analytical method to calculate the scattering of ... more This paper presents an inexpensive but accurate analytical method to calculate the scattering of straight-crested Lamb waves from cracks parallel to the plate surface. The same method is applicable for the disbond problem. In this method, the scatter field is expanded in terms of complex Lamb wave modes with unknown amplitudes. These unknown amplitudes are obtained from the boundary conditions using vector projection utilizing the power expression. The process works by projecting the stress conditions onto the displacement eigen-spaces of complex Lamb wave modes and vice versa. The authors call this technique "complex modes expansion with vector projection" (CMEP). The CMEP approach is versatile and can be readily applied to corrosion, cracks, or disbonds. In this paper, the CMEP method is applied to a horizontal crack in a plate. For verification of the results the authors compared them with the results obtained by using the finite element method (FEM) and literature. The...
Smart Structures and Systems, 2015
Health Monitoring of Structural and Biological Systems 2016, 2016
Volume 6A: Materials and Fabrication, 2015
Piezoelectric Wafer Active Sensors (PWAS) are a viable option for monitoring the structural integ... more Piezoelectric Wafer Active Sensors (PWAS) are a viable option for monitoring the structural integrity of pressure vessels and piping systems. They are inexpensive, small and unobtrusive sensors which can be permanently attached to structures for long term monitoring without interfering with operations, such as operating in areas with limited head space. PWAS are used to inspect the structure through several methods which include; pitch catch or pulse echo wave propagation, and electromechanical impedance spectroscopy. Since the PWAS could be exposed to a range of environmental and/or operating conditions while attached to the structure, the change in the properties and electromechanical characteristics of the sensor must be known at a given condition. Accordingly, there is a need for a testing system which can measure the PWAS properties while exposing the sensor to a wide range of temperatures. The focus in this paper is on elevated temperatures, but the same methodology could be u...
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Papers by Banibrata Poddar