Experimental Study on Fatigue Crack in Welded Crane Runway Girders(I) -Initiation and Propagation of Fatigue Crack-

크레인 거더의 피로균열에 관한 실험적 연구(I) -피로균열의 발생과 진전-

  • Received : 1997.04.10
  • Published : 1997.06.30

Abstract

Three types of fatigue cracks frequently observed in the crane runway girders are verified experimentally using two testing-purpose girders with the size of $6400{\times}600{\times}300$ in millimeters. The fatigue cracks are observed in the vicinity of load-bearing points, at the end of gusset plates and at the fillet welded joints between the lower flange and the web. The load-bearing-point cracks are initiated at the intersection of the fillet welds between the upper flange and the web, where the vertical stiffener is located. The cracks grow up toward the diagonal direction of the web. The cracks observed at the fillet welded joints grow up perpendicularly to the crane runway girder. Compared with the JSSC fatigue design code, the joint class is classified as follows: E for the vicinity of load-bearing points, G or H for the end of gusset plates and D for the lower fillet welded joints. The tests reveal that the class of joint classification at the end of gusset plates and at the lower flange coincides with the fatigue design code.

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