Reverse Bending을 통한 CTOD 시험 예비균열 형상균일화에 관한 연구 = A study on reduction of pre-crack deviation in CTOD specimen using reverse bending method

다국어 초록 (Multilingual Abstract)

This study investigates the appropriate range of reverse bending load for the CTOD test of thick weld by observing improvement of pre-crack shape and determination of the limit applicable load. In order to do it, the effect of the amount of the reverse bending load on the maximum deviation of the pre-crack length was investigated by the extensive tests, and the variation of plastic zone size in way of the crack tip under reverse bending load were evaluated by FEA. With the results obtained by the experiments and FEA, the proper range of reverse bending load was suggested. The effectiveness of the reverse bending method was verified by examining the pre-crack straightness after CTOD tests of thick weld specimens with various thickness and strength.

참고문헌 (Reference)

1 박준식, "선급 극후물 강재 용접부 취성균열 정지특성" 대한용접접합학회지 25 (4) : 9 ~ 15 , 2007

2 HS Reemsnyder, "Residual Stesses and Fatigue Precracking Techniques for Weldment Fracture Toughness Specimens" Journal of Testing and Evaluation 20 (6) ,

3 BS 7448-Part2, "Method for Determination of KIC, critical CTOD and Critical J values of welds in metallic materials" 1997

4 T. Inoue, "Long Crack Arrestability of Heavy-Thick Shipbuilding Steels" Proceedings of International Offshore and Polar Engineering Conference : 132 ~ , 2006

5 M. KOCAK, "Comparision of Fatigue Precracking Methods for Fracture Toughness Testing of Weldments" Proc. Int. Conf. Welding , 1990

6 A. F. Bower, "Applied Mechanics of Solids" CRC Press , 2009

7 S. B Shin, "A Study on Design Criteria of Hatch Coaming Weldment in Ultra-Large Containership on the Basis of Fracture Mechanics" University of Ulsan , 2009