Proposal of Simplified Fatigue Design Method for Side Longitudinals

Abstract

Calculation of local stress from load assessment is needed especially for fatigue design of ship hull. DIScrete Analysis Method (called DISAM for short) is one of the tool to achieve this, but it takes too much time to apply for every new ship in designing stage.
In this paper, simplified fatigue design method for side longitudinals of VLCC is proposed. It is based on beam theory incorporating the results of detailed analysis with DISAM. The proposed method is simple and easy to use and it covers main factors which contribute the structural response of side longitudinals, such as the superposition of multiple loads with phase differences, wave pressure nonlinearity etc.