Imperfection sensitivity of coincident buckling systems

A two-degree of freedom structural system with both buckling loads equal or nearly so is examined, allowing for the presence of small imperfections specified by the values of two general imperfection parameters. A discrete generalized coordinates energy method is used, and the system considered is non-symmetric in the two modes of deflection. Conclusions regarding the types of behaviour possible are obtained by examination of all possible equilibrium path shapes. Comparison is made to behaviour of idealized systems. Change in buckling load value with imperfection size, or imperfection sensitivity, is established and imperfection sensitivity surface forms are sketched.