Free response of twisted plates with fixed support separation

In previous work, Mockenstrurm and Mote investigated the effects of twist o n steady motions of an axially moving plate. It was found that twisting pro duces compressive stresses that increase with twist, aspect ratio. and init ial, longitudinal tension. In this work, we Study the effects of the stress es and non-flat equilibrium produced by twist on the free response. To acco mplish this, the equations of motion are linearized about the equilibrium c onfiguration, yielding a set of three, coupled linens partial differential equations. The equations are discretized and the free response is predicted from the resulting discrete eigenvalue problem. As a function of twist ang le, the natural frequencies first increase and then decrease rapidly to zer o as the compressive lateral stresses become sufficiently large to cause wr inkling. The effects of thickness, aspect ratio, and initial tension on nat ural frequencies are also studied.