A Study on Buckling/Plastic Collapse Strength of Hatch Cover of Bulk Carrier with U-beam Stiffener

Abstract

A hatch cover is not a primary strength member in ship structures. However, if the hatch cover collapses in rough sea, water ingress may happen into the cargo hold, which may result in severe casualty. From this point of view, it is very important to assess the strength of a hatch cover. In CSR (Common Structural Rules) specified by IACS (International Association of Classification Societies), formulas are given to estimate the buckling/ultimate strength of a top panel of a hatch cover. However, these formulas look not adequate. Therefore, in this paper, the CSR formulas regarding the hatch cover strength are assessed on the basis of eigenvalue and nonlinear FEM analyses. At the same time, alternative simple formulas are newly proposed modifying the existing simple formulas, and their applicability is demonstrated.