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Study on the early detection of deterioration and internal demage in an aged structure using elastic wave measurement

利用弹性波测量早期检测老化结构劣化和内部损伤的研究

基本信息

批准号：
61550322
负责人：
OSHIMA Toshiyuki
金额：
$ 1.28万
依托单位：
Kitami Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61550322/
关键词：
Evaluation of Soundness,Elastic Wave Stress Wave Composite Maintenance 散乱波動

项目摘要

It is a well known fact that the stress wave which propagates in a composite with some inclusions takes place the velocity dispersion on a account of both its boundary of the cross sectional area and its composite nature. In this study the scattering of the stress wave propagating in the composites of circular disc and rectangular strip with some damaga model, are investigated. In theoretical calculation, it is assumed that the stress wave in both matrix and inclusion propagates in plane stress condition. Fourier and Hankei trans-form are used inthe tangential direction for composite circular disc. And also fourier transform are used in the both horizontal and vertical direction for rectangular composite strip. Making use of numerical inverse laplace transform and Duhamel integral equation, we have obtained the time histry of the stress wave propagating in the composite. The characteristics of despersion of stress wave velocity on account of the deterioration of the material and crack growing in the composite, are also obtained in the numerical results.In the exeperimental study the dynamic behavior and velocity of a stress wave propagating in the deteriorated composie are investigated using the accoutic testing system. The comparison of peak frequency and deformation of incident stress wave by inclsion between 54 cases of deteriorated structure models are obtained by spectrum analysis and analysis of detected stress wave.

应力波在含有夹杂物的复合材料中传播时，由于其横截面积边界和复合材料的性质，会发生速度频散。本文研究了应力波在具有一定损伤模型的圆盘和矩形条复合材料中的散射问题。在理论计算中，假设应力波在基体和夹杂中均以平面应力状态传播。对复合材料圆盘，切向采用Fourier变换和Hankei变换。并对矩形复合材料条在水平和垂直方向上进行了傅立叶变换。利用数值逆拉普拉斯变换和Duhamel积分方程，得到了应力波在复合材料中传播的时间历程。数值结果还得到了由于材料的劣化和裂纹扩展而引起的应力波传播速度的变化特性，实验研究中利用声学测试系统研究了应力波在劣化复合材料中传播的动力学行为和速度。通过对54个结构模型的应力波频谱分析和实测应力波分析，比较了入射应力波的峰值频率和夹杂变形。