Strength evaluation of intersection between stiffeners and primary supporting members in double hull structure

In this previous study, a consistent theoretical formula was established in single hull structure, taking account of all the structural components affecting the load share of each member, in combination with the combined load effect of direct force from the longitudinal stiffener and shear force on the primary supporting member. What's more, it has been known qualitatively that the bending moment at the root of the web stiffener in double hull structure is less than that in single hull structure. However, the difference between double hull and single hull structures has not been achieved. In this study, the authors develop a theoretical formulation to represent the stresses at the root of the web stiffener due to the load from both the longitudinal stiffener and the shear force on the primary supporting member in the double hull structure. Then, the results calculated by the derived formulae are compared with the results obtained by finite element analysis, and good accuracy of the proposed formula was verified. Finally, the calculated stresses were compared between double hull and single hull structures. On one hand, the share of loading born by the web stiffener is almost comparable between the double hull and single hull structures. On the other hand, the bending moment at the root of the web stiffener is smaller in the double hull structure than in single hull structure, and therefore, the maximum stress is smaller.