scope:

1. Interpretive Review of Weld Fatigue-Strength-Reduction and Stress-Concentration Factors: The objectives of this report are to (1) clarify the current procedures for determining values of fatigue-strength-reduction factors (FSRFs), (2) collect relevant published data on weld-joint FSRFs, (3) interpret existing data on weld-joint FSRFs, (4) facilitate the development of a future database of FSRFs for weld joints, and (5) facilitate the development of a standard procedure for determining the values of FSRFs for weld joints. The main focus of this report is on weld joints in Class 1 nuclear pressure vessels and piping. However, relevant fatigue data on similar weld joints for other applications, such as bridges and offshore structures, also are reviewed and interpreted.

2. Fatigue-Strength-Reduction Factors Based on NDE: This report addresses applying fatigue-strength-reduction factor (FSRE) to a weld surface, based on the nondestructive examination (NDE) that is performed. The development is focused on Class 1, pressure vessels of the ASME Boiler and Pressure Vessel Code, Section III, NB and NC-3200 and Section VIII Division 2 (ASME Code, 1997). It is the position of this report that the fatigue life is a function of the quality of the material and the NDE gives an assessment of this quality. This leads to the conclusion that weld metal will have a fatigue life consistent with the prediction of the ASME Code S-N curves and equivalent to that of base metal provided a full NDE is applied. With reduced NDE, the application of an FSRF in the analysis maintains consistency.

The report develops and defines the basis for each FSRF. For example, it explains why one NDE technique has a greater impact on fatigue life than another technique, i.e., its omission requires a higher FSRF. Publication of this document - WRC Bulletin No. 432 was sponsored by the Pressure Vessel Research Council of the Welding Research Council.