scholarly journals An Optimisation Scheme Based on the Local Interaction Simulation Approach and Lamb Waves for Elastic Property Estimation in Multi-Layered Composites

2012 ◽  
Vol 19 (5) ◽  
pp. 1027-1040 ◽  
Author(s):  
A.B. Spencer ◽  
K. Worden ◽  
W.J. Staszewski ◽  
J.A. Rongong ◽  
N.D. Sims
Keyword(s):  
Elastic Property ◽  
Lamb Waves ◽  
Local Interaction ◽  
Simulation Approach ◽  
Layered Composites ◽  
Property Estimation ◽  
Interaction Simulation

Modeling Guided Waves for Damage Identification in Isotropic and Orthotropic Plates Using a Local Interaction Simulation Approach

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Shankar Sundararaman ◽  
Douglas E. Adams
Keyword(s):  
Lamb Waves ◽  
Wave Length ◽  
Local Interaction ◽  
Wave Form ◽  
Multiple Site ◽  
Simulation Approach ◽  
Orthotropic Plates ◽  
Sharp Interface Model ◽  
Multiple Site Damage ◽  
Interaction Simulation

In this paper, a numerical simulation technique based on the local interaction simulation approach (LISA)/sharp interface model (SIM) is used to study the propagation of Lamb waves in aluminum and orthotropic plates and wave interactions with damage. The LISA/SIM model allows for accurate and fast simulations of sharp changes in material properties across interfaces associated with damage or specimen boundaries. Damage in the form of holes and changes in density and/or stiffnesses are studied for three different plates. These local changes in density and stiffness have dimensions not exceeding the wave length of the interrogating wave form. Wave scatter from these damage sites is shown at different time instants and at specific spatial locations. Multiple site damage cases are studied for all the plate structures. The different scatter patterns associated with intersecting and nonintersecting surface cracks are also studied. Results obtained from a combination of single site damage cases are compared with the composite multiple site damage case to study the usability of commonly applied algorithms for identifying damage. The benefits of observing multiple directions of the displacement field are demonstrated. It is shown that the out-of-plane measurements give a clearer indication of damage sites than the in-plane measurements.

Local Interaction Simulation Approach vs. Finite Element Modelling for Fault Detection in Medical Ultrasonic Transducer

2013 ◽  
Vol 588 ◽  
pp. 157-165 ◽  
Author(s):  
Z. Hashemiyan ◽  
Pawel Packo ◽  
W. Kochański ◽  
Wieslaw Jerzy Staszewski ◽  
Tadeusz Uhl ◽  
...  
Keyword(s):  
Fault Detection ◽  
Finite Element Modelling ◽  
Ultrasonic Transducer ◽  
Poor Quality ◽  
Local Interaction ◽  
Ultrasonic Transducers ◽  
Medical Applications ◽  
Simulation Approach ◽  
Element Modelling ◽  
Interaction Simulation

Ultrasonic transducers are extensively used in medical applications. Any deterioration in their performance can lead to poor quality images. The Local Interaction Simulation Approach (LISA) and Finite Elements are used to model medical ultrasonic transducers. The entire analysis attempts to find out whether the LISA-based methodology could be used for transducer modelling in fault detection applications based on in-air reverberation patterns.

A Method for Acoustic Emission Source Identification Based on Optimisation

2009 ◽  
Vol 413-414 ◽  
pp. 793-801 ◽  
Author(s):  
Andrew Spencer ◽  
Keith Worden ◽  
Gareth Pierce
Keyword(s):  
Acoustic Emission ◽  
High Cycle Fatigue ◽  
Lamb Waves ◽  
Acoustic Emissions ◽  
Ultrasonic Waves ◽  
Cycle Fatigue ◽  
Simulation Approach ◽  
Acoustic Emission Source ◽  
Interaction Simulation ◽  
Pencil Lead

When a metal or composite structure begins to fail, for example due to high cycle fatigue, acoustic emissions caused by the propagation of cracks give rise to bursts of ultrasonic waves travelling through the structure. The health of a structure can be monitored by means of sensors which detect these waves. Acoustic emissions are often generated in experiments by breaking a pencil lead against the surface of the structure in a standardised way but the forces that this imparts are not well understood at present. A Local Interaction Simulation Approach (LISA) algorithm has been implemented to simulate the propagation of ultrasonic waves. This code has been validated against experiments in previous work and has been shown to accurately reproduce the propagation of Lamb waves (including reflections and dispersion etc.) within thin-plate like structures. This paper deals with the use of the LISA code to characterise the forces associated with standard pencil lead breaks. The displacement due to waves emanating from a break is measured and a Differential Evolution (DE) optimisation scheme is used to find the optimal profile of forcing to match the simulation with experiment.

Local interaction simulation approach to modelling nonclassical, nonlinear elastic behavior in solids

2003 ◽  
Vol 113 (6) ◽  
pp. 3049 ◽  
Author(s):  
Marco Scalerandi ◽  
Valentina Agostini ◽  
Pier Paolo Delsanto ◽  
Koen Van Den Abeele ◽  
Paul A. Johnson
Keyword(s):  
Local Interaction ◽  
Elastic Behavior ◽  
Simulation Approach ◽  
Interaction Simulation ◽  
Nonlinear Elastic

scholarly journals Hybrid Global Matrix/Local Interaction Simulation Approach for Wave Propagation in Composites

AIAA Journal ◽  
2015 ◽  
Vol 53 (2) ◽  
pp. 379-393 ◽  
Author(s):  
Matthew B. Obenchain ◽  
Kalyan S. Nadella ◽  
Carlos E. S. Cesnik
Keyword(s):  
Wave Propagation ◽  
Local Interaction ◽  
Simulation Approach ◽  
Interaction Simulation
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