-0(.:, THE 50cIETy OF iiAVALARCHITECT5 AND MARINE ENGINEERS601P,w.ni.Avenue,suite400,JerseyCity,New Jersey07306,.,,,,,.s.!..a,!,,..,,”.S,,”,,”,.,nom,,,,,,S,.,.,,”.,S“,,.,.,,..,,...,..!.,,.rl, ”,!m.4,,,.,., 0.!..,,,.6,*87 A Reliability-Conditioned Approach

one of the areas of marine structural design which could benefit greatly from introducing reliability-based design methods is the design against fatigue failure. Recently, the authors have introduced a new reliability-based design method for fatigue. That method is based on the recently developed Reliability-Conditioned (RC.) method and the Load and Resistance Factor Design (LRFD) code format. The approach utilizes a probabilistic treatment of available S–N fatigue data to generate partial safety factors for use in a simple design equation. In this paper, the Reliability-Conditi.oned fatigue design approach will be further discussed and demonstrated with practical examples. In particular, tbe means for choosing the ‘*most likely failure point,,, and thus tbe partial safety factors for the LRFD format, ia further detailed. The development of a probability dansity function for the equivalent constant anpl itude stres= ranges from the existing stress records of full scale trials will also b.e shown. This development is similar to that currently being investigated under the auspices of the American Association of State Highway and Tra”sportatio” Officials (AASHTO) for estimating fat igue design loads of steel highway bridges. And finally, the means by which the Reliability-Conditioned apprOach could be implemented in a de. ign code and Cal ib?cated to that code is illustrated. 1NTRoDUCTION There are a number of reasons for fatigue cracking of structural detai 1s. These include; poor “workmanship i“ fabrication, poor welding practices, and poor design. In very many cases it has been found that poor design represented the root cause of crackina and failure