Elastic Properties Measurement Using Guided Acoustic Waves

Nondestructive evaluation of elastic properties plays a critical role in condition monitoring of thin structures such as sheets, plates or tubes. Recent research has shown that elastic properties of such structures can be determined with remarkable accuracy by utilizing the dispersive nature of guided acoustic waves propagating in them. However, existing techniques largely require complicated and expensive equipment or involve accurate measurement of an additional quantity, rendering them impractical for industrial use. In this work, we present a new approach that requires only a pair of piezoelectric transducers used to measure the group velocities ratio of fundamental guided wave modes. A numerical model based on the spectral collocation method is used to fit the measured data by solving a bound-constrained nonlinear least squares optimization problem. We verify our approach on both simulated and experimental data and achieve accuracies similar to those reported by other authors. The high accuracy and simple measurement setup of our approach makes it eminently suitable for use in industrial environments.

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Measurement of the elastic properties of evaporated C60 films by surface acoustic waves

Applied Physics A Solids and Surface ◽

10.1007/bf00348425 ◽

1994 ◽

Vol 59 (1) ◽

pp. 83-86 ◽

Cited By ~ 28

Author(s):

H. Coufal ◽

K. Meyer ◽

R. K. Grygier ◽

M. Vries ◽

D. Jenrich ◽

...

Keyword(s):

Elastic Properties ◽

Acoustic Waves ◽

Surface Acoustic Waves ◽

C60 Films

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Estimation of elastic properties of nuclear fuel material using longitudinal ultrasonic velocity – A new approach

Journal of Nuclear Materials ◽

10.1016/j.jnucmat.2006.12.045 ◽

2007 ◽

Vol 366 (1-2) ◽

pp. 129-136 ◽

Cited By ~ 21

Author(s):

K.K. Phani ◽

Dipayan Sanyal ◽

A.K. Sengupta

Keyword(s):

Elastic Properties ◽

Nuclear Fuel ◽

Ultrasonic Velocity ◽

New Approach ◽

Fuel Material

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Measurement of Scattering Coefficients

Physical Ultrasonics of Composites ◽

10.1093/oso/9780195079609.003.0012 ◽

2011 ◽

Author(s):

Dale Chimenti ◽

Stanislav Rokhlin ◽

Peter Nagy

Keyword(s):

Wave Propagation ◽

Reflection Coefficient ◽

Transmission Coefficient ◽

Elastic Properties ◽

Volume Fraction ◽

Ultrasonic Field ◽

Guided Wave ◽

Scattering Coefficient ◽

Elastic Behavior ◽

Scattering Coefficients

In the previous chapters, we saw how waves in composites behaved under various circumstances, depending on material anisotropy and wave propagation direction. The most important function that describes guided wave propagation, and the plate elastic behavior on which propagation depends, is the reflection coefficient (RC) or transmission coefficient (TC). More generally, we can call either one simply, the scattering coefficient (SC). It is clear that the elastic properties of the composite are closely tied to the SC, and in turn the scattering coefficient determines the dispersion spectrum of the composite plate. Measuring the SC provides a route to the inference of the elastic properties. To measure the SC, we need only observe the reflected or transmitted ultrasonic field of the incident acoustic energy. In doing so, however, the scattered ultrasonic field is influenced by several factors, both intrinsic and extrinsic. Clearly, the scattered ultrasonic field of an incident acoustic beam falling on the plate from a surrounding or contacting fluid will be strongly influenced by the RC or TC of the plate material. The scattering coefficients are in turn dependent on the plate elastic properties and structural composition: fiber and matrix properties, fiber volume fraction, layup geometry, and perhaps other factors. These elements are not, however, the only ones to determine the amplitude and spatial distribution of energy in the scattered ultrasonic field. Extrinsic factors such as the finite transmitting and receiving transducers, their focal lengths, and their placement with respect to the sample under study can make contributions to the signal as important as the SC itself. Therefore, a systematic study of the role of the transducer is essential for a complete understanding and correct interpretation of acoustic signals in the scattered field. The interpretation of these signals leads ultimately to the inference of composite elastic properties. As we pointed out in Chapter 5, the near coincidence under some conditions of guided plate wave modes with the zeroes of the reflection coefficient (or peaks in the transmission coefficient) has been exploited many times to reveal the plate’s guided wave mode spectrum.

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A New Approach for Relating Dynamic Elastic Properties and Geomechanical Parameters Based on Rock Physics Modeling

7th EAGE Saint Petersburg International Conference and Exhibition ◽

10.3997/2214-4609.201600214 ◽

2016 ◽

Author(s):

M.F. Ghasemi ◽

I.O. Bayuk ◽

Y. Alkhimenkov

Keyword(s):

Elastic Properties ◽

Rock Physics ◽

New Approach ◽

Geomechanical Parameters ◽

Rock Physics Modeling ◽

Physics Modeling ◽

Dynamic Elastic Properties

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Extraction of a Dynamic Multiport Compact Thermal Model for a Silicon Microthruster

Journal of Microelectronics and Electronic Packaging ◽

10.4071/1551-4897-1.1.30 ◽

2004 ◽

Vol 1 (1) ◽

pp. 30-38

Author(s):

M. Salleras ◽

J. Palacin ◽

I. García ◽

M. Puig ◽

J. Samitier ◽

...

Keyword(s):

Thermal Model ◽

Nonlinear Least Squares ◽

Element Model ◽

Search Algorithms ◽

Sequential Search ◽

Complete Structure ◽

Fem Model ◽

Hybrid Combination ◽

Least Squares Optimization ◽

Thermal Simulations

In this work, a methodology to extract dynamic multiport compact thermal model from finite element model (FEM) thermal simulations is presented. The proposed methodology is applied to an innovative silicon microthruster. The boundary conditions of the FEM model have been estimated from experimental measurements. The analysis of these transients with the methodology presented delivers a dynamic multiport compact RC model representation of the complete structure. The topology and sizing of the components is provided by a hybrid combination of Sequential Search algorithms together with nonlinear least squares optimization.

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Least Squares Optimization: From Theory to Practice

Robotics ◽

10.3390/robotics9030051 ◽

2020 ◽

Vol 9 (3) ◽

pp. 51 ◽

Cited By ~ 2

Author(s):

Giorgio Grisetti ◽

Tiziano Guadagnino ◽

Irvin Aloise ◽

Mirco Colosi ◽

Bartolomeo Della Corte ◽

...

Keyword(s):

Computer Vision ◽

Least Squares ◽

Open Source ◽

State Of The Art ◽

Nonlinear Least Squares ◽

Research Community ◽

Specific Domain ◽

Theory To Practice ◽

Least Squares Optimization ◽

Computer Vision Systems

Nowadays, Nonlinear Least-Squares embodies the foundation of many Robotics and Computer Vision systems. The research community deeply investigated this topic in the last few years, and this resulted in the development of several open-source solvers to approach constantly increasing classes of problems. In this work, we propose a unified methodology to design and develop efficient Least-Squares Optimization algorithms, focusing on the structures and patterns of each specific domain. Furthermore, we present a novel open-source optimization system that addresses problems transparently with a different structure and designed to be easy to extend. The system is written in modern C++ and runs efficiently on embedded systemsWe validated our approach by conducting comparative experiments on several problems using standard datasets. The results show that our system achieves state-of-the-art performances in all tested scenarios.

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SENSITIVITY SHAPING WITH DEGREE CONSTRAINT BY NONLINEAR LEAST-SQUARES OPTIMIZATION

IFAC Proceedings Volumes ◽

10.3182/20050703-6-cz-1902.01028 ◽

2005 ◽

Vol 38 (1) ◽

pp. 499-504 ◽

Cited By ~ 2

Author(s):

Ryozo Nagamune ◽

Anders Blomqvist

Keyword(s):

Least Squares ◽

Nonlinear Least Squares ◽

Degree Constraint ◽

Least Squares Optimization

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A Social Enterprise Approach to Empowering Micro, Small and Medium Enterprises (SMEs) in Indonesia

Journal of Open Innovation Technology Market and Complexity ◽

10.3390/joitmc6030050 ◽

2020 ◽

Vol 6 (3) ◽

pp. 50 ◽

Cited By ~ 2

Author(s):

Irfan Ridwan Maksum ◽

Amy Yayuk Sri Rahayu ◽

Dhian Kusumawardhani

Keyword(s):

Social Welfare ◽

Social Enterprise ◽

Small And Medium Enterprises ◽

Critical Role ◽

New Approach ◽

Indonesian Government ◽

The Social ◽

Medium Enterprises ◽

Depth Interviews ◽

Micro Enterprises

Micro-enterprises play a critical role in the Indonesian economy, in which they supply 99.8% of the country’s employment and account for more than 95% of all enterprises in Indonesia. However, these firms experience many impediments, including a lack of capital, skills, and technology, which creates poor competitiveness. Although the Indonesian government has implemented many policies to deal with these problems, none have been adequate in improving the capacity and productivity of micro, small, and medium enterprises (SMEs). The empowerment program “Iptekda LIPI—Penerapan dan Pemanfaatan Ilmu Pengetahuan dan Teknologi di Daerah Lembaga Ilmu Pengetahuan Indonesia (LIPI)—The Technology for Region Program of the Indonesian Institute of Sciences” proposed a new approach using a social enterprise to solve this issue. This paper analyses the social-enterprise approach of Iptekda LIPI which incorporates market and social welfare to determine the problems experienced by SMEs. The researchers conducted in-depth interviews with the owners of SMEs in West and East Java to explore how this approach may contribute to their businesses and to analyze the challenges of the social enterprise approach in empowering SMEs.

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