Plate field

A plate field is the rectangular zone of shell or deck plating bounded by adjacent stiffeners and supporting members, the basic unit for local strength and buckling checks. Its short side is the stiffener spacing and its long side the frame spacing or web-frame interval. Under lateral pressure the field acts as a plate clamped along its edges, and the required thickness follows t proportional to spacing times sqrt(pressure / permissible stress). Under in-plane hull-girder compression the same field is checked for elastic and ultimate buckling, with the critical stress depending on the aspect ratio and edge conditions. Class rules treat the plate field and its stiffener together as a stiffened panel for the combined assessment.