2841 赤外線応力画像システムを用いた溶接継手の疲労き裂検出(S37-4 非破壊評価とモニタリング(4),S37 非破壊評価とモニタリング)

抄録

The theromoelastic stress imaging system, which is a stress analysis technique based on the measurement of infrared emission from the surface of a body subjected to cyclic loading, was applied to inspection of the fatigue crack initiated at a weld toe in a welded joint. The fatigue crack detected by this technique was smaller than 0.6mm in depth, and the values of crack length estimated from the stress images were agreed with crack lengths measured by the optical microscope well. Also, stress intensity factor ranges ΔK were evaluated from stress distribution around a crack tip measured by this imaging system. The values of ΔK evaluated from stress measurements tended to be larger than analytical values.