The Mechanics of Prepreg Conformance

Abstract

Experiments are reported and mathematical models are developed to describe the me chanics of prepreg conformance to a substrate. Two distinctly different behaviors are identi fied for graphite epoxy prepregs, called: 1) pressure driven lay-up behavior, and 2) surface tension driven lay-up behavior. In the first case it is shown that there is a force-velocity superposition principle that applies to the lay-up parameters. In the second case, the ap plied force is unimportant. For both cases an upper bound on the lay-up speed is observed and mathematical models are developed to describe the phenomena. Reasons for the dif ferent behavior, and applications to lay-up of prepregs in machine tools are discussed.