Application of Fracture Mechanics to Prevention and Control of Subcritical Crack Growth and Fracture in Advanced High-Performance Ship Structures
Advanced surface craft and ships such as hydrofoils and surface-effect ships represent one area in the ship structures design field where fracture mechanics must be applied for prevention of fracture and control of crack growth. These vehicles feature the unique problem of weight-critical, monolithic structures fabricated of high-strength metals operating in an aggressive environment at exceptionally high levels of performance.
The integrity of high-performance surface craft and ships depends on both the resistance to propagation of cracks and resistance to fracture of the structural material. Design procedures based on engineering application of fracture mechanics principles to assure structural integrity have been established. These procedures enable designers to systematically take into account applicable metal crack tolerance parameters and their relation to structural performance. The three-part Ratio Analysis Diagram (RAD) system, developed to provide an analysis technique for determining the significance of stress-corrosion cracking, sustained load cracking, and fracture in terms of critical flaw size and stress level, is presented. Considerations on the effects of electrochemical coupling on corrosion fatigue and stress-corrosion cracking are also discussed.
Unable to display preview. Download preview PDF.
- 1.Brown, B.F., “A New Stress-Corrosion Cracking Test for High-Strength Alloys”, Mater. Res. Stand., 6 (1966), 129–33.Google Scholar
- 2.Novak, S.R. and Rolfe, S.T., “Comparison of Fracture-Mechanics and Nominal-Stress Analyses in Stress-Corrosion Testing”, United States Steel Corporation, Monroeville, Pa., Naval Ship Engineering Center Contract Report No. ARL-B-63105, December 1968. (AD 846 125L)Google Scholar
- 4.Novak, S.R. and Rolfe, S.T., “Modified WOL Specimen for KIscc Environmental Testing”, United States Steel Corporation, Monroeville, Pa., Naval Ship Engineering Center Contract Report, May 1968. (AD 836 310L)Google Scholar
- 5.“Damage Tolerant Design Handbook. A Compilation of Fracture and Crack Growth Data for High-Strength Alloys Including Data Sheets for the First Supplement”, Metals and Ceramics Information Center, Battelle Columbus Labs., Ohio, Report No. MCIC-HB-01-Suppl-l, September 1973. (AD 772 810)Google Scholar
- 6.Judy, R.W., Jr., and Goode, R.J., “Stress-Corrosion Cracking of High-Strength Steels in Titanium Alloys”, Weld. J., 51 (1972), 437s–48s.Google Scholar
- 7.Stress-Corrosion Cracking in High Strength Steels and in Titanium and Aluminum Alloys, ed. by B.F. Brown. Washington, D.C.: Naval Research Laboratory, 1972.Google Scholar
- 8.Pellini, W.S., “Criteria for Fracture Control Plans”, Naval Research Laboratory, Washington, D.C., Report No. NRL-7406, May 1972. (AD 743 058)Google Scholar
- 9.Pellini, W.S., personal communication.Google Scholar
- 10.“Standard Method of Test for Plane-Strain Fracture Toughness of Metallic Materials”, Designation: E399–72, in 1973 Annual Book of ASTM Standards, Part 31. Philadelphia: Am. Soc. for Testing and Materials (1973), 960–79.Google Scholar
- 11.Yoder, G.R., Griffis, C.A. and Crooker, T.W., “Sustained-Load Cracking of Titanium: A Survey of 6A1–4V alloys”, Naval Research Laboratory, Washington, D.C., Report No. NRL-7596, August 1973. (AD 767 307)Google Scholar
- 12.Crooker, T.W., “Designing Against Structural Failure Caused by Fatigue Crack Propagation”, Naval Eng. J., 84, no. 6 (1972). 46–56.Google Scholar