The effect of pad plates at intersection of hull structural members has been discussed qualitatively for some time, now but has not yet been elucidated quantitatively.
Recently, pad plates have often been used as reinforcement when large derrick posts are installed or as a remedy when cracks have occurred at corners of superstructures or at the top and bottom of hold frames on ships in service.
The purpose of this study is to find the effect of pad plate's dimensions on strength, thereby contributing to the determination of the appropriate pad plate dimensions.
An outline of the study is as follows.
(1) Fatigue Tests
Standard S-N diagrams were obtained to estimate the fatigue strength required to design pad plates for various combinations of parameters such as the thickness, width, root gap of pad plates and the kind of load.
(2) Analysis
Stress analysis and K value (stress magnification factor) analysis of the fatigue test results were made by the finite element method and the beam theory, and an analysis method for fatigue strength of pad plates was established.