CRACK ARREST IN MILD STEEL PLATES

Unstable fast brittle cracks in mild steel plates were arrested in an increasing G-field using Robertson gradient crack arrest tests. A quantitative analysis of the mechanics of crack arrest is presented in which a quasi- static assumption is made to calculate in G-field, and using dynamic crack propagation data obtained from precracked Charpy impact tests; the crack arrest temperature predicted by this analysis is about 20 deg C greater than measured values. The analysis focuses attention on the importance of shear lips on the arrest mechanism; a semi- quantitative analysis of the shape of the arrested crack front is made, and in principle, the effects of applied stress and plate thickness on the arrest mechanism are predictable. Empirical correlations between specified Charpy impact energies (which are directly related to shear-lip energies) and crack arrest temperatures appear to have some physical justification. Conversely it is possible to determine the crack propagation properties of the material from the crack arrest data; a procedure for this is presented.

• Corporate Authors:

  Effects Technology, Incorporated

  5383 Hollister Avenue
  Santa Barbara, CA  United States  93105
• Authors:
  • Wilshaw, R
• Publication Date: 1974-12

Media Info

• Features: References;
• Pagination: 23 p.

Subject/Index Terms

• TRT Terms: Cracking; Crash tests; Fracture mechanics
• Uncontrolled Terms: Crack propagation
• Old TRIS Terms: Crack arrest
• Subject Areas: Marine Transportation; Materials; Research;

Filing Info

• Accession Number: 00099922
• Record Type: Publication
• Source Agency: Ship Structure Committee
• Report/Paper Numbers: TR 74-33
• Files: TRIS
• Created Date: Oct 18 1975 12:00AM