SECONDARY BUCKLING OF A STRUT ON AN ELASTIC FOUNDATION UNDER AXIAL COMPRESSION
弹性基础上的杆在轴压下的二次屈曲

In this paper, the post- buckling behavior of an elastic pinended strut on an elastic foundation is studied.Attention is focused on those values of foundation stiffness at which,under axial load, the two lowest buckling loads of the strut are near.At first,we reveal the secondary buckling of the strut by means of Liapunov-Schmidt reduction and analyses of stability;furthermore,give the asymptotical unfolding of the primary post-buckling branches and secondary branches based on bifurcation equation.Secondly,numerical conputations of the secondary buckling of the strut is made by the method which have been developed by the author of this paper.The numerical results are in agreement with the asymptotical expression very well.