<p>Rigid plastic methods are useful tools for predicting large deformation resistance of framed structures in ultimate and accidental limit states. Most existing rigid plastic solutions are for beam cross sections with two axes of symmetry, e. g. rectangular and circular cross sections. Application of rigid plastic methods to cross sections with one axis of symmetry remains limited and not fully understood. This paper focuses on stiffened panels that are crucial structural components in marine structures, and their cross sections have only one axis of symmetry. Rigid plastic solutions for large deformation resistance of one-bay stiffened panels are revisited. Different plastic interaction functions in the literature are reviewed and discussed, which shall lay a common ground for analyzing the problem. Explicit expressions for the interaction functions of stiffened panel cross sections are derived and presented in a compact form using the center of gravity (COG) as the reference axis for bending moment calculation. This paper further demonstrates that the solutions proposed by Yu et al. (2018) remain exact when the newly derived interaction functions are applied. In addition, for a stiffened panel comprising multiple bays, membrane actions from the plate flange perpendicular to the stiffener direction become important. Expressions for the corresponding membrane contributions from plate flanges in the transverse direction are also derived. The proposed analytical models are validated against nonlinear finite element simulations using a stiffened panel that is representative of a semisubmersible platform column in the North Sea, demonstrating generally good agreement. The proposed solutions can be useful for the analysis and design of stiffened panels subjected to extreme and abnormal loads such as collisions, explosions and ice actions.</p>