主题词:Stability of equilibrium,Static and dynamic bifurcations,Bifurcation parameters,Bifurcation diagrams,Pitchfork, Trans-critical and limit-point Bifurcations,Hopf bifurcations, limit cycles,Buckling and post-buckling of elastic structures,Static perturbation methods,Critical load,Effect of imperfections,Buckling of beam and systems of beams