INFLUENCE OF WELD POROSITY ON THE INTEGRITY OF MARINE STRUCTURES

A study is discussed that examined the influence of porosity on the fatigue resistance of ship steel weldments. A literature review was conducted to determine parameters that were found to control the fatigue life of welds having porosity. A predictive model was developed incorporating those parameters to account for both crack initiation and propagation. Four types of porosity--single pore porosity, uniform porosity, co-linear porosity, and cluster porosity--were examined using the model. The model's sensitivity to the parameters (plate thickness, stress ratio, residual stress, pore size and porosity type) was studied. A variable amplitude loading history was developed from SL-7 loading history data, and used to predict actual service lives. The main conclusion of the study was that porosity has an insignificant effect in welds when the weld reinforcement is left intact. If the reinforcement were to be removed, the type and size of porosity would control fatigue life. Among all types of porosity studied, cluster porosity was found to have the greatest effect on crack initiation and propagation. When subjected to the service history, the welds were predicted to last through their normal design life. Finally, the results are related to the American Bureau of Shipping's Rules for Nondestructive Inspection of Hull Welds. The code was found to be conservative from a fatigue standpoint.

  • Supplemental Notes:
    • Report; A Ship Structure Committee Report
  • Corporate Authors:

    Battelle

    Columbus, OH  United States 

    United States Coast Guard

    2100 Second Street, SW
    Washington, DC  United States  20593
  • Authors:
    • Walsh, W J
    • LEIS, B N
    • Yung, J Y
  • Publication Date: 1990-8-2

Media Info

  • Features: References;
  • Pagination: 111 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00661003
  • Record Type: Publication
  • Source Agency: Maritime Technical Information Facility
  • Report/Paper Numbers: SSC-334
  • Contract Numbers: DTCG23-85-C-20077
  • Files: TRIS
  • Created Date: Jul 21 1994 12:00AM