Inelastic Deformation of Plate Panels.

Ship plate panel often experience inelastic deformation due to loads normal to their surface such as ice pressure, green water, slamming, docking, wheel loads and low energy collision. However, criteria for assessing the need to repair panels deformed in-service are not readily available. Design guidelines are available that restrict the allowable levels of inelastic deformation in new construction. This report presents the results of an experimental and analytical investigation related to establishing criteria for assessing the amount of plastic deformation that may be permitted on existing ship structures without compromising structural integrity. The work included the review of existing criteria for panel deformation, measurement of plate panel deformation on existing ships, finite element analysis to establish strain vs. deflection relationships for ship plate panels, and an assessment of the efforts, a methodology is proposed for determining the maximum inelastic deformation that should be permitted for ship steel structural panels.