Large inelastic deformation resistance of stiffened panels subjected to lateral loading

Abstract

This paper presents a simplified formulation for the assessment of large deformation resistance of stiffened panels subjected to lateral loading. The method is based on rigid plastic material assumptions and the use of yield functions formulated in terms of stress resultants. The method considers the flexibility of the panel ends with respect to inward motion, while the rotational boundary conditions are free or clamped. Concentrated and distributed loads are considered, as is patch loading. The resistance-deformation curves predicted by the proposed method are compared with results from experiments and using LS-DYNA, and good agreement is obtained for panels that are not dominated by shear failure and tripping or local buckling of stiffeners at the early stage of deformation. The formulation provides a useful tool for quick estimates of panels subjected to abnormal or accidental static and transient lateral loads such as ship collisions, dropped objects, explosions, slamming, hydrostatic pressure and ice actions.

Analytical Method for Evaluating the Impact Response of Stiffeners in a Ship Side Shell Subjected to Bulbous Bow Collision

“…e compared curves demonstrate that the discrepancy of the resistance-penetration responses is small in the experiments, which proves that the tripping of the central stiffener has a slight influence on the resistance response. Clearly, this conclusion is different from that stated by Yu et al [20]. e reason for this difference is attributed to the variations in the structural forms of the central stiffener in these two studies.…”

“…e reason for this difference is attributed to the variations in the structural forms of the central stiffener in these two studies. e investigated stiffener in Yu et al [20] is the T-profile stiffener, where the top flange will experience a remarkable membrane tension effect. Tripping of the T-profile stiffener can reduce the lateral deflection of the top flange, thereby leading to a significant decrease in resistance.…”

“…where w csmax is the maximum deflection of the central stiffener, l cs is the length of the central stiffener, F e_cs is the external load at the elastic stage, M e_cs (x) is the moment in the stiffener applied by F e_cs and can be obtained as M e_cs � F e_cs x/ 2, E is the elastic modulus, and I cs is the moment of inertia. In the pure bending state, the neutral axis for the stiffened panel is located in the plate, and the stiffener dominates the bending effect [20]. I cs can be expressed as…”

Shared-Energy Prediction Model for Ship-Ice Interactions

“…Both plate and frame models are examined independently, but to also consider some interaction effects the plate is modelled as a flange in the frame analysis. With this approach, the plate is modelled as a large flange attached to the bottom of the frame, where the plate flange spans the distance between the frames [35,45].…”

“…Analytical models are the most common models and are often used during the preliminary design phase, structural optimization, and risk assessment, due to their simplicity, speed, and low resource cost [22,32]. These models tend to consider plastic analysis and failure, by describing the material and structural failure through the internal and external mechanics of a collision [33,34,35]. Analytical models typically apply energy methods and momentum conservation to determine the structural response of a collision [22,31,36,37].…”