Divergence and flutter instability of elastically restrained structures under follower forces

Abstract

The instability of elastically restrained simple structures acted upon by compressive follower forces is discussed by using a static stability analysis. From this investigation it is concluded that depending on the amount of elastic restraint: (a) divergence or flutter type instability is possible and (b) the critical load of a divergence type non-conservatively loaded structure may be higher or smaller than the critical load of the corresponding structure subjected to a conservative load. Moreover, a lower bound theorem is presented according to which under a certain condition the load carrying capacity of a non-conservatively loaded structure of divergence type is higher than the load carrying capacity of the corresponding conservatively loaded structure. From the foregoing findings a better insight into the actual mechanism of loss of stability of structures under follower forces is gained.