MARINE ENVIRONMENT EFFECTS ON FATIGUE CRACK PROPAGATION IN GRP LAMINATES FOR HULL CONSTRUCTION

The effects of a salt water environment on the fatigue properties of a particular GRP laminate construction, suitable for hull construction, are examined experimentally. The experimental S-N curves for both an air and a salt water environment are given and comparison of the two curves shows a general, but moderate, decrease in the fatigue life of the material in a salt water environment. A recently developed theory for fatigue crack growth in composite materials is used as the basis for comparison of experimental data obtained for the relationship between fatigue crack growth rate and stress intensity factor. The theory is confirmed for the specific material used in this study when a linear approximation to the S-N curves is made. Further, the mechanism of fatigue crack growth is confirmed as one of ligament advance. Additional experimental work to refine the theory is recommended.

• Supplemental Notes:
  • Index No. 73-316-cfo
• Corporate Authors:

  Massachusetts Institute of Technology

  Sea Grant Program, 77 Massachusetts Avenue
  Cambridge, MA  United States  02139
• Authors:
  • Demchik, R P
  • Mandell, J F
  • McGarry, F J
• Publication Date: 1973-11-30

Media Info

• Pagination: 77 p.

Subject/Index Terms

• TRT Terms: Composite materials; Cracking; Fatigue (Mechanics); Fatigue cracking; Glass fiber reinforced plastics; Stresses
• Uncontrolled Terms: Fatigue life; Stress intensity factors
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00048378
• Record Type: Publication
• Source Agency: Massachusetts Institute of Technology
• Report/Paper Numbers: MITSG-73-16
• Files: TRIS
• Created Date: Nov 14 1974 12:00AM