永久伸びによるワイヤロープの安全性の判定
1973 年 89 巻 1029 号 p. 721-725
詳細
1973 年 89 巻 1029 号 p. 721-725
The impact test has practiced to investigate the decreasing trend of impact value and the maximum elongation rate, on deteriorated wire ropes which have damages such as corrosion, abrasion and wire breakage individually.
From the test, it has become clear that both the impact value and the maximum elongation rate decrease as deterioration of wire rope progresses, and that there is a certain relation between the decreasing trends of them. The relation is realized on both the deteriorated wire rope caused only by one type of damage defected artificially and the retired wire rope which has various types of damage.
The impact value is one of the characteristics that estimate the safety of wire rope, therefore, it seems possible to estimate the safety of wire rope based on the remaining ratio of the maximum elongation rate i. e. the remaining length against the allowable maximum elongation.
But, in case that tht sharp flaws and deteriorations which decrease cross-sectional area of the wire rope partially are recognized on the surface, it may be necessary to practice the manual inspection or some nondestructive testing methods, because the elongation of wire rope is not clearly realized in spite of sharp reduction of the cross-sectional area.
