Introduction of Some Researches on Electromagnetic NDT
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カテゴリ: 第7回
Zhenmao CHEN,Toshiyuki TAKAGI 1. Introduction
In this article, recent research works related to Electromagnetic Nondestructive Evaluation ENDE) that are conducted in NDT Lab of Xi'an iaotong University partly in cooperation with Cohuku University are briefly introduced. Eddy Current Testing (ECT) techniques, Direct Current Potential (DCPD), Electromagnetic Acoustic Cesting (EMAT) and some new NDT techniques are pgraded and proposed for applications to the nspection of key structural components of nuclear ower plant and some other structures of new naterials such as ultra-light material and Thermal Barrier Coating (TBC). The backgrounds, technical pproaches, and some typical results are described.At first, developments on the NDT method for wo typical ultra-light materials - metallic foam and netallic lattice sandwich plate are introduced. Proposal and validation of NDT methods for nspection of delamination and coating thickness eduction of TBC are presented then with Calidations based on numerical simulations. Third, upgrading of inversion techniques of Stress Corrosion Cracks (SCC) to improve the sizingrecision is described. Finally, a strategy for Listinguishing SCC and fatigue crack, and some zsearches on the NDT of mechanical damage in ustenitic stainless steel based on natural magnetic ield are given.Contact information: Prof. Zhenmao Chen, 28 West Xianning Road, Xi'an, 710049, China. School of Aerospace, Xi'an Jiaotong University, Tel/Fax: 86-29-82668736, E-mail: chenzm@mail.xjtu.edu.cn2. Inspection of Ultra-light MaterialUltra-light material is novel and multifunctional material which has advantages of high strength, high stiffness and low density, and widely applied in many ndustries, such as aerospace engineering, transportation etc. There are two typical ultra-light materials, one is the Foam material and the other is the material of lattice structure. Up to now, there are still no satisfactory NDT echniques being established yet for the Pre-Service PSI) and In-Service Inspection (ISI) of the ultra-light material and structure. Considering the features of the ENDE, inspection method of metallic foam and metallicattice sandwich plates are studied in our group, and a strategy based on the ECT and the DCPD method has been developed. The research works related to this topic are as follows:1) Inspection of metallic foam [1]Metallic Foam (MF) possesses features including super lightness and high mechanical energy absorption. The fabrication method of MF is mainly a Erothing technique. There may occurs large bubble Elaws in MF during the process of frothing manufacturing, i.e., some vicinal small bubbles may anite to a large cavity flaw which will greatly affect the performance of MF. Therefore, Pre-Service InspectionPSI) with NDT approach for the inner bubble flaws is mportant before the material is used.Considering the features of the metallic foam, DCPD method is selected for the inspection of the bubble flaw. To evaluate the performance of the method, efficient numerical simulation methods are Heveloped based on 3D FEM and a pre-calculated Hatabase of scalar potential. Numerical simulation Ehows that there is a good possibility of DCPD method to detect an inner bubble flaw if it is not very
“ “Introduction of Some Researches on Electromagnetic NDT“ “Zhenmao CHEN,Toshiyuki TAKAGI
In this article, recent research works related to Electromagnetic Nondestructive Evaluation ENDE) that are conducted in NDT Lab of Xi'an iaotong University partly in cooperation with Cohuku University are briefly introduced. Eddy Current Testing (ECT) techniques, Direct Current Potential (DCPD), Electromagnetic Acoustic Cesting (EMAT) and some new NDT techniques are pgraded and proposed for applications to the nspection of key structural components of nuclear ower plant and some other structures of new naterials such as ultra-light material and Thermal Barrier Coating (TBC). The backgrounds, technical pproaches, and some typical results are described.At first, developments on the NDT method for wo typical ultra-light materials - metallic foam and netallic lattice sandwich plate are introduced. Proposal and validation of NDT methods for nspection of delamination and coating thickness eduction of TBC are presented then with Calidations based on numerical simulations. Third, upgrading of inversion techniques of Stress Corrosion Cracks (SCC) to improve the sizingrecision is described. Finally, a strategy for Listinguishing SCC and fatigue crack, and some zsearches on the NDT of mechanical damage in ustenitic stainless steel based on natural magnetic ield are given.Contact information: Prof. Zhenmao Chen, 28 West Xianning Road, Xi'an, 710049, China. School of Aerospace, Xi'an Jiaotong University, Tel/Fax: 86-29-82668736, E-mail: chenzm@mail.xjtu.edu.cn2. Inspection of Ultra-light MaterialUltra-light material is novel and multifunctional material which has advantages of high strength, high stiffness and low density, and widely applied in many ndustries, such as aerospace engineering, transportation etc. There are two typical ultra-light materials, one is the Foam material and the other is the material of lattice structure. Up to now, there are still no satisfactory NDT echniques being established yet for the Pre-Service PSI) and In-Service Inspection (ISI) of the ultra-light material and structure. Considering the features of the ENDE, inspection method of metallic foam and metallicattice sandwich plates are studied in our group, and a strategy based on the ECT and the DCPD method has been developed. The research works related to this topic are as follows:1) Inspection of metallic foam [1]Metallic Foam (MF) possesses features including super lightness and high mechanical energy absorption. The fabrication method of MF is mainly a Erothing technique. There may occurs large bubble Elaws in MF during the process of frothing manufacturing, i.e., some vicinal small bubbles may anite to a large cavity flaw which will greatly affect the performance of MF. Therefore, Pre-Service InspectionPSI) with NDT approach for the inner bubble flaws is mportant before the material is used.Considering the features of the metallic foam, DCPD method is selected for the inspection of the bubble flaw. To evaluate the performance of the method, efficient numerical simulation methods are Heveloped based on 3D FEM and a pre-calculated Hatabase of scalar potential. Numerical simulation Ehows that there is a good possibility of DCPD method to detect an inner bubble flaw if it is not very
“ “Introduction of Some Researches on Electromagnetic NDT“ “Zhenmao CHEN,Toshiyuki TAKAGI