EVALUATION OF FATIGUE TESTS AND DESIGN CRITERIA ON WELDED DETAILS.
Since the fatigue resistance provisions of the AASHTO Specifications were developed from test data documented in NCHRP Reports 102 and 147, several major fatigue studies have been conducted. By reviewing the results of these studies on full scale, welded steel test specimens, the original database was broadened to include a wider range of detail types and sizes. Each data group was compared to the existing AASHTO fatigue design provisions in order to determine the adequacy of the resistance curves and to check for detail types whose fatigue strengths deviate from these curves. From this review, a revised set of fatigue design curves is proposed that better estimates the fatigue resistance of welded steel bridge details. Though they are similar to the current AASHTO curves, the new curves are more uniform and parallel; each curve is set at a constant slope of minus 3. 0. The available data have been compared with the appropriate curve in order to assess the validity of the proposed fatigue design curves. Although the database has been significantly enlarged by the inclusion of new test data, several areas have been identified that require further in-depth study. This would help to better establish the constant amplitude fatigue limits.
author list (cited authors)
Keating, P. B., & Fisher, J. W.
National Cooperative Highway Research Program Report