| Budget Amount *help |
¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1998: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Research Abstract |
In our previous researches, we proposed new techniques to identify parameters of a finite element model, i.e. the density and the modulus of elasticity, of two types of cantilever beam, by using an image processing technique. One beam was a combined beam, the other a damaged beam with a small crack. To identify the parameters of a small segment of the combined beam, spline smoothing with symmetrization and the weighted Tikhonov regularization technique were used. In addition, to detect the size and the location of a small crack, a new type of Simulated Annealing method was proposed.
In this research, we develop our technique to detect a damage in the two dimensional structure and to reduce the calculation time in the SA method.
We get following results.
(1) Instead of using the CM type FEM model, we reduced the calculation time by using the dynamic stiffness matrix dramatically.
(2) Using above technique, we can precisely estimate the location and magnitude of a small crack with less calculation.
(3) The semi-rotational stiffness coefficient was proposed as the index to represent the damage of the joint failure in the structure. After reducing the effect of noise in the image data, the precious semi-rotational stiffness coefficient was estimated.
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