Effects of material properties and crush conditions on the crush energy absorption of fiber composite rods

Abstract

Crushing along the fiber axis of undirectional E-glass fiber composites rods was examined to determine the effects of fiber volume fraction, fiber diameter, matrix compressive yield strength, crush rate, fiber surface treatment, and crush plate geometry. The volume specific energy absorption was found to increase with fiber content, fiber diameter, matrix yield strength, and crush rate. The crush load stability was found to be independent of fiber content and fiber diameter but not of matrix yield strengt. The crush load became less stable as the yield strength increased. The crush behavior of specimens containing clean fibers was about the same as with sized fibers, but specimens with a release agent on the fiber surface crushed with less energy absorption that decreased even as the fiber content increased, but the crush load was more stable than with sized or clean fibers. The volume specific energy absorption was greater when the rod specimens were crushed against concave surfaces than against a flat plate. A relatively simple model was able to account for the dependence of the energy absorption on fiber volume fraction and matrix yield strength.