Buckling/plastic collapse behaviour and strength of stiffened plates under thrust

Series of elastoplastic large deflection analyses are performed ion stiffened plates with flat-bar and angle-bar stiffeners subjected to thrust, and the influences of sectional geometries of stiffeners on the buckling/plastic collapse behaviours are investigated. It has been found that: (1) Local panel buckling strength between stiffeners, post-buckling inplane rigidity and ultimate strength are significantly increased owing to the stiffener. (2) Stiffened plates undergo elastoplastic secondary buckling after local panel buckling. (3) Higher ultimate strength is attained by stiffeners with lower depth to thickness ratio of a web. However, the reduction in capacity after the ultimate strength is more rapid for stiffened plates with such stiffeners. (4) When the stiffeners with relatively high depth to thickness ratio are provided, the ultimate strength is lower than the case with lower depth to thickness ratio, but the capacity reduction after the ultimate strength is rather moderate.