U.S. Department of EnergyOffice of Scientific and Technical Information
Early detection of fatigue crack initiation in a weldment by a system composed of a laser microscope and a video microscope
Abstract
An important problem related to the maintenance of a welded structure is how to find fatigue cracks while they are still shorter than the critical length. Fatigue cracks in a welded structure frequently initiate from weld areas, most commonly some surface irregularities such as microcracks, undercuts, and craters. The authors have found that a system composed of a scanning laser microscope (SLM) and a portable video microscope (PVM) is extremely useful for early detection of initiation of a fatigue crack in a weldment. Using this system it is possible to detect fatigue cracks only a few microns long with virtually no treatment of the surface. The PVM is portable, and it is suited for an inspection of a larger area for detecting the existence of a crack at a magnification up to approximately 600 times. The SLM can be moved but hardly portable. However, it is suited for detailed examination up to approximately 6,000 times. Information obtained in either the SLM or the PVM is obtained on a monitor of a personal computer. In fact, in the system installed at the Department of Ocean Engineering, M.I.T., the two microscopes share the same monitor and printer. The information can be observedmore »
- Authors:
-
- Massachusetts Inst. of Technology, Cambridge, MA (United States). Dept. of Ocean Engineering
- Publication Date:
- OSTI Identifier:
- 27921
- Report Number(s):
- CONF-940230-
ISBN 0-7918-1266-9; TRN: IM9516%%46
- Resource Type:
- Book
- Resource Relation:
- Conference: 13. international conference on offshore mechanics and Arctic engineering (OMAE-13), Houston, TX (United States), 27 Feb - 3 Mar 1994; Other Information: PBD: 1994; Related Information: Is Part Of OMAE 1994. Volume 3: Materials Engineering; Salama, M.M.; Toyoda, Masao; Lui, S.; Dos Santos, J.F.; Kocak, M.; Patterson, E.A.; Berge, S. [eds.]; PB: 438 p.
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; STEELS; WELDED JOINTS; CRACK PROPAGATION; MICROSTRUCTURE; MICROSCOPY; SAMPLE PREPARATION; EXPERIMENTAL DATA; SCANNING ELECTRON MICROSCOPY; FAILURES; IN-SITU PROCESSING
Citation Formats
Masubuchi, K, Cushing, J M, Tannery, P, and Olsen, E. Early detection of fatigue crack initiation in a weldment by a system composed of a laser microscope and a video microscope. United States: N. p., 1994.
Web.
Masubuchi, K, Cushing, J M, Tannery, P, & Olsen, E. Early detection of fatigue crack initiation in a weldment by a system composed of a laser microscope and a video microscope. United States.
Masubuchi, K, Cushing, J M, Tannery, P, and Olsen, E. 1994.
"Early detection of fatigue crack initiation in a weldment by a system composed of a laser microscope and a video microscope". United States.
@article{osti_27921,
title = {Early detection of fatigue crack initiation in a weldment by a system composed of a laser microscope and a video microscope},
author = {Masubuchi, K and Cushing, J M and Tannery, P and Olsen, E},
abstractNote = {An important problem related to the maintenance of a welded structure is how to find fatigue cracks while they are still shorter than the critical length. Fatigue cracks in a welded structure frequently initiate from weld areas, most commonly some surface irregularities such as microcracks, undercuts, and craters. The authors have found that a system composed of a scanning laser microscope (SLM) and a portable video microscope (PVM) is extremely useful for early detection of initiation of a fatigue crack in a weldment. Using this system it is possible to detect fatigue cracks only a few microns long with virtually no treatment of the surface. The PVM is portable, and it is suited for an inspection of a larger area for detecting the existence of a crack at a magnification up to approximately 600 times. The SLM can be moved but hardly portable. However, it is suited for detailed examination up to approximately 6,000 times. Information obtained in either the SLM or the PVM is obtained on a monitor of a personal computer. In fact, in the system installed at the Department of Ocean Engineering, M.I.T., the two microscopes share the same monitor and printer. The information can be observed by several people, it can be stored on a video tape, and it also can be printed on a paper. This paper describes results obtained in three series of experiments using (a) bead-on-plate specimens in low-carbon steel, (b) low-carbon steel specimens with several types of surface discontinuities, and (c) specimens taken from butt welds in high-strength steels.},
doi = {},
url = {https://www.osti.gov/biblio/27921},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Dec 31 00:00:00 EST 1994},
month = {Sat Dec 31 00:00:00 EST 1994}
}