Steel wire rope has a complicated structure that is made by twisting a large number of steel wires together. We propose finite-element modeling for the analysis of the magnetic flux leakage testing of wire rope. The first step is modeling a simple model for analysing the state of magnetization of the wire rope under a magnetic yoke, where wire rope is considered to be a pipe. In the second step, a detailed model is used for the evaluation of flux leakage around wire breaks, where the wire rope is expressed as a single bundle of straight wires or strands. The results obtained from these numerical analyses of the proposed models are useful for quantitative evaluation of wire rope testing.

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The fracture behavior of semi-elliptical surface cracks and quarter-elliptical cracks formed in glass plates by the application of thermal stress is investigated using an optical interferometric technique. First, the accuracy of the technique in evaluating the stress intensity factor K_I using the interferometric method employing white light is discussed. The K_I values obtained using this technique are shown to be in close agreement with theoretical values. Subsequently, the distributions of K_I along the crack front of semi-elliptical surface cracks with various aspect ratios are experimentally analyzed, and the experimental K_I values are shown to coincide approximately with the theoretical values calculated using the Raju-Newman equation. Moreover, crack extension behavior is observed by interferometric fringe pattern analysis and is shown to correspond to the distribution of K_I, which is determined based on variations in the crack shape. Finally, the K_I value for the quarter-elliptical crack with the small aspect ratio is almost constant along the crack front, and the crack is shown to extend uniformly in all directions. However, when the aspect ratio is large, the K_I value is very large at the surface point on the tensile side of the specimen and remarkable crack extension is observed in this area.

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