Influence of Weld Porosity on the Integrity of Marine Structures
Abstract
This study examined the influence of porosity on the fatigue resistance of ship steel weldments. A literature review was conducted to determine parameters which have been found to control the fatigue life of welds containing porosity. A predictive model was developed incorporating those parameters to account for both crack initiation and propagation. Four types of porosity; single pore, uniform porosity, co-linear porosity, and cluster porosity, were examined using the model. The models sensitivity to the parameters (plate thickness, stress ratio, residual stress, pore size and porosity type) was studied and discussed. A variable amplitude loading history was developed from SL-7 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 is of little concern in welds if the weld reinforcement is left intact. If the reinforcement is removed, the type and size of porosity will control fatigue life. When subjected to the service history the welds were not predicted to fail during any 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. Keywords: Welds porosity; Fatigue; Variable amplitude loading; Low cycle fatigue; Linear elastic fracture mechanics.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1989
- Accession Number
- ADA227369
Entities
People
- Brian N. Leis
- J. Y. Yung
- William J. Walsh
Organizations
- Battelle Memorial Institute