Effect of the Frequency of the Cyclic Load to the Inverse Analyses of the Heat Conduction in Infrared Thermography

2006 ◽  
Vol 326-328 ◽  
pp. 1137-1140 ◽  
Author(s):  
Kenji Machida ◽  
Shohei Miyagawa
Keyword(s):  
Heat Conduction ◽  
Infrared Thermography ◽  
Hybrid Method ◽  
Inverse Analysis ◽  
Measurement Method ◽  
Cyclic Load ◽  
Stress Measurement ◽  
Hybrid Analysis ◽  
Element Analysis ◽  
Stress Components

Influence of the frequency to the temperature image obtained by an infrared thermography was investigated using specimens of three kinds of materials at four kinds of frequencies of the cyclic load. Then, the infrared hybrid method was developed to separate individual stress components. However, the influence of heat conduction is inevitable in the infrared stress measurement method. Therefore, an error arises in the infrared hybrid analysis. Then, the system which corrects the error by the inverse analysis was developed. Thereby, the accuracy of the stress intensity factor was able to be raised. Furthermore, the accuracy of hybrid method considering to heat conduction was discussed in comparison with the 3-D finite element analysis and 2-D hybrid method.

Influence of the Thickness and Frequency in the Infrared Hybrid Method in Consideration of Heat Conduction

2007 ◽  
Vol 345-346 ◽  
pp. 1287-1290
Author(s):  
Kenji Machida ◽  
Koichi Hayafune ◽  
Shohei Miyagawa
Keyword(s):  
Heat Conduction ◽  
Hybrid Method ◽  
Inverse Analysis ◽  
Measurement Method ◽  
Stress Measurement ◽  
Hybrid Analysis ◽  
Element Analysis ◽  
Stress Components ◽  
Metal Materials ◽  
Conduction Error

The thickness dependency of the temperature image obtained by an infrared thermography was investigated using specimens with three kinds of metal materials of different heat conduction and four kinds of thickness of the specimens. Then, the infrared hybrid method was developed to separate each stress components. However, it contains the influence of heat conduction in the infrared stress measurement method. Therefore, heat conduction error will arise in the infrared hybrid analysis. Then, the new system which corrects the error by an heat conduction inverse analysis was developed. Thereby, the accuracy of the stress intensity factor was able to be raised using heat conduction inverse analysis. Furthermore, the accuracy of hybrid method taking heat conduction into consideration was discussed in comparison with 3-D finite-element analysis and the 2-D infrared hybrid method.

Influence of the Thickness and Frequency in the Infrared Hybrid Method in Consideration of Heat Conduction

2007 ◽  
Vol 353-358 ◽  
pp. 3092-3095
Author(s):  
Kenji Machida ◽  
Shohei Miyagawa
Keyword(s):  
Stress Intensity Factor ◽  
Heat Conduction ◽  
Hybrid Method ◽  
Inverse Analysis ◽  
Cyclic Load ◽  
Measuring Method ◽  
Hybrid Analysis ◽  
Element Analysis ◽  
Stress Components ◽  
Stress Measuring

Recently, the influence of heat conduction has been considered to be a big problem. Then, the influence of heat conduction was investigated by the experiment which changed the material, thickness of the specimen and frequency of a cyclic load. Then, the infrared hybrid method was developed to separate individual stress components. However, it has the influence by heat conduction in the infrared stress measuring method. Therefore, an error will arise in the infrared hybrid analysis. Then, the system which corrects the error by the inverse analysis was developed. Thereby, the accuracy of the stress intensity factor was able to be raised. Furthermore, the accuracy of hybrid method considering to heat conduction was discussed in comparison with the 3-D finite-element analysis and 2-D hybrid method.

Influence of the Thickness of the Specimen in the Infrared Hybrid Method in Consideration of Heat Conduction

2006 ◽  
Vol 321-323 ◽  
pp. 841-844 ◽  
Author(s):  
Kenji Machida ◽  
Shohei Miyagawa
Keyword(s):  
Finite Element Analysis ◽  
Stress Intensity Factor ◽  
Heat Conduction ◽  
Hybrid Method ◽  
Inverse Analysis ◽  
Measuring Method ◽  
Hybrid Analysis ◽  
Element Analysis ◽  
Stress Components ◽  
Stress Measuring

The thickness dependency of the temperature image obtained by an infrared thermography was investigated using specimens with three kinds of materials and four kinds of the thickness of the specimen. Then, the infrared hybrid method was developed to separate individual stress components. However, it had the influence by heat conduction in the infrared stress measuring method. Therefore, an error will occur in the infrared hybrid analysis. Then, the system which corrected the error by the inverse analysis was developed. Thereby, the accuracy of the stress intensity factor was able to be raised. Furthermore, the accuracy of hybrid method considering to heat conduction was discussed in comparison with the 3-D finite-element analysis and 2-D hybrid method.

Dual-Axis Hole-Drilling ESPI Residual Stress Measurements

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Gary S. Schajer ◽  
Michael Steinzig
Keyword(s):  
Residual Stress ◽  
Measurement Errors ◽  
Measurement Method ◽  
Stress Measurement ◽  
Experimental Tests ◽  
Optical Data ◽  
Hole Drilling ◽  
Similar Response ◽  
Plane Normal ◽  
Stress Components

A novel dual-axis ESPI hole-drilling residual stress measurement method is presented. The method enables the evaluation of all the in-plane normal stress components with similar response to measurement errors, significantly lower than with single-axis measurements. A numerical method is described that takes advantage of, and compactly handles, the additional optical data that are available from the second measurement axis. Experimental tests were conducted on a calibrated specimen to demonstrate the proposed method, and the results supported theoretical expectations.

Influence of the Material and Thickness of the Specimen on an Infrared Stress Image

2004 ◽  
Vol 261-263 ◽  
pp. 1641-1646
Author(s):  
Kenji Machida ◽  
Mamtimin Gheni
Keyword(s):  
Thermal Conductivity ◽  
Hybrid Method ◽  
Thermal Conduction ◽  
Crack Problem ◽  
High Stress ◽  
High Accuracy ◽  
Problem Analysis ◽  
Principal Stresses ◽  
Distribution Form ◽  
Stress Components

The thickness dependency of the temperature image obtained by an infrared thermography was investigated using specimens with three kinds of materials and four kinds of the thickness of the specimen. Only the sum of the principal stresses which is the first invariant of stress tensor is measured, and it is impossible to measure individual stress components directly. Then, the infrared hybrid method was developed to separate individual stress components. Although the form of the contour line of low stress side differs greatly, the distribution form of high stress side was considerably alike. The stress intensity factor of material with low thermal conductivity can be estimated with high accuracy by the infrared hybrid method. On the crack problem, it was elucidated that the influence of thermal conduction is large and an inverse problem analysis is required.

Residual Stress Measurement and Simulation of 3C-SiC Single and Poly Crystal Cantilevers

2010 ◽  
Vol 645-648 ◽  
pp. 865-868 ◽  
Author(s):  
Ruggero Anzalone ◽  
Massimo Camarda ◽  
Daniel Alquier ◽  
M. Italia ◽  
Andrea Severino ◽  
...  
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Stress Measurement ◽  
Bulk Material ◽  
Raman Shift ◽  
Silicon Substrates ◽  
Free Standing ◽  
Element Analysis ◽  
Micro Fabrication ◽  
Sic Films

The fabrication of SiC MEMS-based sensors requires new processes able to realize microstructures on either bulk material or on the SiC surface. The hetero-epitaxial growth of 3C-SiC on silicon substrates allows one to overcome the traditional limitations of SiC micro-fabrication. In this work a comparison between single crystal and poly crystal 3C-SiC micro-machined structures will be presented. The free-standing structures realized (cantilevers and membrane) are also a suitable method for residual field stress investigation in 3C-SiC films. Measurement of the Raman shift indicates that the mono and poly-crystal 3C-SiC structures release the stress in different ways. Finite element analysis was performed to determine the stress field inside the films and provided a good fit to the experimental data. A comprehensive experimental and theoretical study of 3C-SiC MEMS structures has been performed and is presented.

Parameter identification of concrete dams using swarm intelligence algorithm

2017 ◽  
Vol 34 (7) ◽  
pp. 2358-2378 ◽  
Author(s):  
Siqi Dou ◽  
Junjie Li ◽  
Fei Kang
Keyword(s):  
Parameter Identification ◽  
Swarm Intelligence ◽  
Inverse Analysis ◽  
Arch Dam ◽  
Hydraulic Structures ◽  
Concrete Dams ◽  
Concrete Gravity Dam ◽  
Element Analysis ◽  
Content Type ◽  
Fireworks Algorithm

Purpose Parameter identification is an important issue in structural health monitoring and damage identification for concrete dams. The purpose of this paper is to introduce a novel adaptive fireworks algorithm (AFWA) into inverse analysis of parameter identification. Design/methodology/approach Swarm intelligence algorithms and finite element analysis are integrated to identify parameters of hydraulic structures. Three swarm intelligence algorithms: AFWA, standard particle swarm optimization (SPSO) and artificial bee colony algorithm (ABC) are adopted to make a comparative study. These algorithms are introduced briefly and then tested by four standard benchmark functions. Inverse analysis methods based on AFWA, SPSO and ABC are adopted to identify Young’s modulus of a concrete gravity dam and a concrete arch dam. Findings Numerical results show that swarm intelligence algorithms are powerful tools for parameter identification of concrete structures. The proposed AFWA-based inverse analysis algorithm for concrete dams is promising in terms of accuracy and efficiency. Originality/value Fireworks algorithm is applied for inverse analysis of hydraulic structures for the first time, and the problem of parameter selection in AFWA is studied.

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