Viscoelastic Behavior Of Foamed Polystyrene/Paper Composites

This paper outlines a simple lab experiment for high school students or freshman engineering students designed to demonstrate the principle behind why sandwich composites are so stiff as well as light-weight. A sandwich composite consists of a very lightweight core (such as a foamed polymer or honeycomb structure) with sheets of another material (such as paper, plastic, fiberglass, or aluminum) on the top and bottom surfaces. Applications for sandwich composites requiring both high-stiffness and lightweight include aircraft panels, boat hulls, jet skis, snow skis, partitions, and garage doors. In this experiment, the students measure the increase in stiffness when the top and bottom skins of paper are added to a Styrofoam beam to form the sandwich composite. Also this experiment includes a creep test in which the students measure and plot the deflection of the Styrofoam beam versus time to illustrate the viscoelastic behavior of Styrofoam.