An enhanced exponential matrix approach aimed at the stability of piecewise beams on elastic foundation

In this paper, an enhanced exponential collocation method for the stability assessment of piecewise beams resting on elastic foundation and subjected to both non-uniform distributed and concentrated loads is presented. The exponential basis functions usually adopted in literature are enriched with trigonometric functions that make the eigenvalue analysis well-posed without reducing the original simplicity of the method. A measure of the error occurring from the proposed approach and its improvement are also proposed. Several examples aimed at estimating the buckling loads under typical end supports are discussed. A comparison with exact and with other numerical results that are available in literature are carried out. Such a comparison shows the high accuracy and the fast convergence of the proposed approach.