EFFECT OF A STOP HOLE AS AN EMERGENCY MEASURE AT SEA TO STOP CRACK PROPAGATION OF A HULL MEMBER

Drilling a hole at the end of a crack to stop it from propagating is a well-known emergency measure. The authors propose a numerical evaluation of its effect. In the case of a crack initiated at the midship part of a strength deck, the authors calculate the stress concentration distribution around the crack and the stopholes at its ends. Their study shows that the stress concentration factor of the hole decreases with the ratio of stop hole radius to crack length. This means that the hole is effective when the crack is short and the largest convenient drill is used. The stress concentration factor can be considerably reduced in this way. The safe operating time is judged from fatigue crack initiation at the hole but it is concluded that the crack should be repaired as quickly as possible where the factor is greater than 7 and the ship is sailing in a severe sea zone in winter.

• Supplemental Notes:
  • J. Japan Inst. Nav., 80 (1989), p.9 (Mar.) [8 pp., 5 ref., 5 tab., 7 fig.]
• Authors:
  • Mano, H
  • Kawabe, H
• Publication Date: 1989

Language

• Japanese

Subject/Index Terms

• Uncontrolled Terms: Crack initiation; Crack propagation; Stress intensity factors
• Subject Areas: Marine Transportation;

Filing Info

• Accession Number: 00695517
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Aug 14 1995 12:00AM