Plate/Stiffener Assemblies under Nonuniform Edge Compression

Abstract

The paper investigates the behavior of plate and stiffener assemblies under nonuniform compressive stress. The first part deals with the buckling behavior and the second part investigates postbuckling response. With stiffeners assumed to possess finite rotation capacity, a general expression is derived for the prediction of the elastic buckling of the assembly under this general loading condition. The accuracy of the derived expression, also obtained numerically using the Galerkin method, is compared with other available data for the two limiting conditions of rotationally free and clamped unloaded boundaries. Results show that the prediction is within a 5% difference. The influence of rotational restraint and stress gradient upon the buckling load and the associated buckling mode is also investigated. In the second part, the investigation is extended to the postbuckling range. The compatibility differential equation is first solved analytically and then an approximate solution of the equilibrium equation is obtained using the Galerkin method. Explicit expressions are derived for the load deflection, ultimate strength, and membrane stress distributions. Analytical effective-width formulations based on the characteristics of the stress field of the buckled plate are proposed for this general loading condition. The predicted load-deflection expression is compared with independent test results.