Development of the DCPD Method Based on Finite Element Analysis for Measuring Semi-Elliptical Surface Cracks

반타원 표면균열 형상측정을 위한 유한요소 전기장 해석에 기초한 직류전위차법의 개발

Kim, Yeong-Jin;Sim, Do-Jun;Choe, Jae-Bung

  • Published : 2001.07.01


One of major problems in analyzing failure mechanism of real components is the accurate measurement of crack size and shape. The DCPD(Direct Current Potential Drop) method has been widely used for the crack measurement of a structure and finite element analysis has been used for the derivation of calibration equations, which relates the potential drop with the crack depth. In this paper, finite element analyses were performed for semi-elliptical surface cracks with various crack shapes(a/c) and crack depths(a/t). As a result, a calibration equation has been derived for the measurement of a semi-elliptical surface crack in wide plates. Analytical results are compared with experimental results to evaluate the validity and the applicability of the derived equation. The proposed method is expected to provide efficient and accurate measurement of a surface crack during crack growth.


DCPD Method;Finite Element Analysis;Surface Crack;Crack Configuration Measurement


  1. Enmark, M., Lucas, G. and Odette, G.R., 1992, 'An Electric Potential Drop Technique for Characterizing Part-Through Surface Cracks,' Journal of Nuclear Materials 191-194, pp. 1038-1041
  2. Ikeda, K., Yoshimi, M. and Miki, C., 1991, 'Electrical Potential Drop Method for Evaluating Crack Depth,' International Journal of Fracture, Vol. 47, pp. 25-38
  3. Saka, M., Hirota, D., Abe, H. and Komura, I., 1998, 'NDE of a 3-D Surface Crack Using Closely Coupled Probes DCPD Technique,' Journal of Pressure Vessel Technology-Transactions of the ASME, Vol. 120, No. 4, pp. 374-378
  4. 주석재, 1996, '안정피로성장 중인 표면균열 형상변화의 해석,' 대한기계학회논문집(A) 제20권 제9호, pp. 2843-2853
  5. ABAQUS User's manual, 2000, Hibbitt, Karlsson & Sorensen, Inc.
  6. ASTM E647, 1995, Standard Test Method for Measurement of Fatigue Crack Growth Rates, 1995 Annual Book of ASTM Standards, Vol. 3.01, pp. 594-599
  7. 심도준, 박호림, 최재붕, 김영진, 2000, '표면균열 형상측정을 위한 다채널 DCPD 시스템의 개발,' 한국가스학회지 제4권 제1호, pp. 49-54