| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2003: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2002: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
This project is an experimental study on an application of Carbon Fiber Reinforced Polymer strip, hereinafter called CFRP strip, to repair of a fatigue crack. The study was done for two years in 2002 to 2003.
In 2002, fatigue tests were performed using a specimen with the crack which was repaired by patching the CFRP strip after drilling stop holes at the crack tips. It was known from the results of the tests that an endurance limit of the repaired specimen was increased according to increase of width of the CFRP strip. Even if width of the CFRP strip was shorter than the crack length, fatigue life was increased rapidly in the region of the low stress range. Therefore, it was able to be said that the repair effect had shown up notably.
In 2003, fatigue tests were performed using a specimen with the crack which was repaired by only patching the CFRP strip. In this case, an endurance limit was not shown in all types of specimen. However, therewassufficient effect in an improvement of fatigue life. And, the wide CFRP strip showed higher repair effect than narrow CFRP strip. In addition, even when width of the CFRP strip was shorter than the crack length, it was judged that this method was enough practically as a first-aid repair. Moreover, the higher repair effect was shown in the region of the high stress range.
From the above-mentioned studies, it was clear that the CFRP strip was applicable to repair of a fatigue crack with or without a stop hole. Possibility of practical use of the CFRP strip can be said to be high.
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