TY - GEN
T1 - Nonlinear ultrasonic techniques for nondestructive damage assessment in metallic materials
AU - Kim, J. Y.
AU - Jacobs, L. J.
AU - Qu, J.
PY - 2011
Y1 - 2011
N2 - This paper presents an overview of the application of nonlinear ultrasonic (NLU) techniques to characterize materials; it has been demonstrated that NLU can provide quantitative inputs to determine the material state and measure damage in engineering components. It has recently been shown that NLU can be used to develop the framework for accurate life prediction of fatigue damaged components. These NLU measurements are done at the material level, before the formation of micro- and macro-cracks. The traditional NDE of damage of a material subject to fatigue starts from the time when a small crack initiates because there is no measurable macroscopic change in the material prior to the crack initiation. In most metallic materials, however, cracks in a measurable size appear quite late (after 80%) in the total life, while the material's integrity in terms of toughness and strength gradually decreases due to the microplasticity (dislocations) and associated change in the material' microstructure. Starting from mechanics fundamentals, we first develop the theoretical equations of wave motion in an elastic solid with quadratic nonlinearity. The next section considers measurement techniques for NLU, which is followed by examples of the assessment of fatigue damage in metals with NLU.
AB - This paper presents an overview of the application of nonlinear ultrasonic (NLU) techniques to characterize materials; it has been demonstrated that NLU can provide quantitative inputs to determine the material state and measure damage in engineering components. It has recently been shown that NLU can be used to develop the framework for accurate life prediction of fatigue damaged components. These NLU measurements are done at the material level, before the formation of micro- and macro-cracks. The traditional NDE of damage of a material subject to fatigue starts from the time when a small crack initiates because there is no measurable macroscopic change in the material prior to the crack initiation. In most metallic materials, however, cracks in a measurable size appear quite late (after 80%) in the total life, while the material's integrity in terms of toughness and strength gradually decreases due to the microplasticity (dislocations) and associated change in the material' microstructure. Starting from mechanics fundamentals, we first develop the theoretical equations of wave motion in an elastic solid with quadratic nonlinearity. The next section considers measurement techniques for NLU, which is followed by examples of the assessment of fatigue damage in metals with NLU.
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M3 - Conference contribution
AN - SCOPUS:84866705496
SN - 9781605950532
T3 - Structural Health Monitoring 2011: Condition-Based Maintenance and Intelligent Structures - Proceedings of the 8th International Workshop on Structural Health Monitoring
SP - 531
EP - 538
BT - Structural Health Monitoring 2011
T2 - 8th International Workshop on Structural Health Monitoring 2011: Condition-Based Maintenance and Intelligent Structures
Y2 - 13 September 2011 through 15 September 2011
ER -