Characterization of Curing Composites Using a Bi-material Beam Technique

摘要

Thermo-mechanical characterization of a curing polymer matrix composite is difficult as the material transforms from a liquid to a solid state during cure. Traditionally, very different techniques have been used in the liquid and in the solid state. This paper presents a technique where an uncured composite is laminated on top of a metal shim, creating a bi-material beam. The bi-material beam is then cured in a dynamic mechanical analyzer while subject to thermo-mechanical loading. By choosing the thermo-mechanical loading appropriately, modulus development, cure shrinkage, and thermal expansion can be determined for the composite during the entire cure process. The technique is very efficient and allows material properties required for process analysis to be determined quickly and accurately. This paper outlines the principles of the technique together with data reduction and validation based on bi-material steel-Lexan samples.