抄録
This paper describes summarized results of the fatigue analysis on deck of a bulk carrier and webframe of a car carrier using measured stress data which are obtained through onboard tests. Fatigue analysis based on measured stress data plays an important role for investigation of fatigue strength of actual hull structures.
Frequency distribution of stress ranges is estimated from short term parameters of fluctuating stress. Both accumulated fatigue damage and fatigue damage during rough seas are calculated. Following relations between stress level and fatigue damage, relation between wind and sea conditions and fatigue damage etc. are also reviewed.
The results show that rough seas fairly affect the accumulated fatigue damage and that fatigue damage during specific rough seas are considerable. It is also found that narrow sphere of rather low stress range affects fatigue damage of the deck of bulk carrier and that wide sphere of stress range affects fatigue damage of the webframe of car carrier. As to wind and sea conditions it is shown that fatigue damage of the deck of bulk carrier during rough seas grows rapidly as dominant wind scale exceeds 7 under swell scale 7 and upward.
