THE EFFECT OF SPRINGING RESPONSE OF A TLP ON TETHER FATIGUE

The purpose of this paper is to investigate the effect on estimated fa tigue damage of TLP tethers of the method used To model the springing response. In particular, the goal has been to look into the consequenc e for long-term fatigue calculation of modeling the springing response as a second-order, sum-frequency process as opposed to assuming that the springing response is Gaussian. It is shown that with a standard e ngineering approach to the calculation of long-term fatigue damage, th is effect is in fact marginal. However, the deviation between the nume rical estimates of the quadratic transfer function describing the spri nging response as provided by different computer codes is found to pro duce estimates of the long-term fatigue that exhibit substantial varia bility.