Post-buckling response of elastic-plastic beam resting on an elastic foundation to eccentric axial load

摘要

The post-buckling response of an elastic-plastic beam resting on a Winkler-type elastic foundation to an eccentric axial load is investigated. A nonlinear beam element is formulated and employed in computing the post-buckling paths and limit points. The numerical results show that the post-buckling behaviour of the beam is unstable, and the post-buckling strength, measured in term of a ratio between the axial load and the critical load, increases with an increment in the foundation stiffness. The limit load, which the beam can withstand, is sensitive to the eccentricity and it gradually reduces when raising the eccentricity, regardless of the foundation stiffness. The elastic foundation support increases the axial load at the initial yield point, but it reduces the mid-span deflection at the point, and this effect is more pronounced for the foundation having higher stiffness, regardless of the eccentricity.