THE EFFECT OF LACK OF PENETRATION DEFECTS ON STATIC TENSILE BEHAVIOR OF HIGH-STRENGTH STRUCTURAL STEEL WELDMENTS
This paper investigates the effect of lack of penetration (LOP) in welded T-1 steel plates on tensile properties. Tensile tests of welded plates having varying sizes of LOP were conducted and monitored for acoustic emissions. Fracture surfaces were examined. Using a documented computer program the J integral of fracture mechanics was evaluated at several points for each specimen. An anticipated decrease in tensile strength and ductility with increasing LOP was observed. The fracture surface was found to pass in and out of the weld metal, the extent depending on LOP. The J integral analysis showed that welded T-1 steel joints with LOP are well approximated by the rigid-plastic model. This permits a critical value of the J integral to be computed from the load and deflection at peak load. There appears to be a critical LOP value below which the J integral is not valid. Moreover, the fracture occurs in the base metal for LOP less than one critical value, and in the weld metal for LOP greater than a second critical value higher than the first. For intermediate LOP values, failure occurs in the weld metal, but gross elongation occurs in the base metal. By using base metal yield and tensile strength, a net section criterion and a limit load stress, four modes of fracture behavior can be identified. These modes indicate three ranges of influence of LOP size on fracture. For LOP size less than a lower critical value, base metal dominates fracture. For LOP size greater than a larger critical value, LOP size controls fracture. For intermediate LOP size, the LOP dominates but does not fully control fracture.
Army Construction Engineering Research LaboratoryP.O. Box 4005
Champaign, IL United States 61820
- Lawrence Jr, F V
- Cox, E P
- Honing Jr, E M
- Publication Date: 1975-2
- Features: Appendices; Figures; References; Tables;
- Pagination: 42 p.
- TRT Terms: Computer programs; Defects; Fracture mechanics; High strength steel; Pendulum tests; Steel plates; Tensile properties; Weldments
- Uncontrolled Terms: Fracture
- Subject Areas: Geotechnology; Highways; Materials;
- Accession Number: 00096485
- Record Type: Publication
- Report/Paper Numbers: CERL-IR-M-123 Final Rpt.
- Files: TRIS
- Created Date: Aug 13 1975 12:00AM