权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of Identification Method of Defects Embedded in a Body by A.C.Electromagnetic CT Method Using Inverse Analysis of Frequency Response

利用频率响应反分析的交流电磁CT法识别体内缺陷的方法的开发

基本信息

批准号：
07555349
负责人：
KUBO Shiro
金额：
$ 1.41万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

The present investigators proposed the D.C.electric potential CT (computed tomography) method for identification of two- and three- dimensional cracks embedded in an electric conductive body. The usefulness of the method was shown by numerical simulations and experiments. In this study, by extending the D.C.electric potential CT (computed tomography) method, A.C.electric potential CT defect identification method was proposed, in which electric potential distribution for several A.C.frequencies were used to identify the crack. The main conclusions obtained are summarized in the followings.1. Electromagnetic field of cracked body was analyzed using boundary element method to construct calibration relation between A.C.potential and crack length.2. A.C.electric potential distributions were measured for a body with a through crack. It was found that the calibration relation worked well.3. The electric potential distribution was calculated, in the case that the frequency was high and the skin effect was significant.4. Electric potential distribution in a three-dimensional surface crack was measured. It was found the electric potential distributions in the limits of high and low frequencies may be effective to identify the crack.5. Crack identification was made using full three-dimensional electromagnetic field analysis. It was found that the method was useful.6. For the identification of plural cracks fusion type genetic algorithm was proposed.7. Identifiction of interface crack in dissimilar materials was made by extending the method. Nemerical simulations and experiments showed the usefulness of the method.

目前的研究人员提出了直流电位CT（计算机断层扫描）的方法来识别二维和三维裂纹嵌入在导电体。数值模拟和实验结果表明了该方法的有效性。在本研究中，通过扩展直流电位CT（计算机断层扫描）方法，交流电位CT缺陷识别方法，其中的电位分布的几个交流频率来识别裂纹。主要结论归纳如下：1.采用边界元法分析了裂纹体的电磁场，建立了交流电位与裂纹长度的标定关系.本文测量了含裂纹物体的交流电位分布。结果表明，该校准关系式具有良好的适用性.计算了高频集肤效应显著情况下的电位分布.测量了三维表面裂纹中的电位分布。发现高频和低频范围内的电位分布可以有效地识别裂纹。裂纹识别采用全三维电磁场分析。结果表明，该方法是有效的.针对多裂纹的识别，提出了融合型遗传算法.通过对该方法的推广，实现了对异种材料界面裂纹的识别。数值模拟和实验表明了该方法的有效性。