Spectral Fatigue Analysis of a Transportation Barge

摘要

Fatigue failure has become one of the most significant concerns inrnoffshore marine field. Offshore floating structures like transportationrnbarges are subjected to cyclic loading during voyages because ofrnchaotic sea environment. Random sea wave induces the cyclic stress inrnthe structure, result in sudden local failure of the structure element.rnThis may cause the loss of barge and costly offshore modules which arerncarried by the barge such as top sides, jackets. During its life time,rnbarge experiences so many loading conditions, contributing to fatiguerndamage.rnAt design stage, an adequate factor for safety has been considered forrnthe loads encountered during its lifetime. But due to great uncertaintiesrninvolved in fatigue failure, it is not possible to determine the fatigue lifernaccurately. Among various existing methods available for thernprediction of fatigue life, spectral fatigue method is considered to bernmore realistic approach by taking real sea state energy spectrum intornaccount and is very convenient to use at the preliminary stage of designrnfor the estimation of the fatigue life as compared to other methods.rnHere a study is made to find fatigue damage of the transportation bargernbased on spectral analysis.