Analysis of Failure Behavior of Polymeric Composite Materials with the Method of Acoustic Emissions (Abstract)

Abstract

Different types of composite materials have been tested with acoustic emission methods. The variables considered were the polyester foam density, the fiber content, and the fiber legth. The specimens were tested in a tensile mode until fracture; during the test the acoustic emission was monitored and registered on magnetic tape. The fracture surfaces have been analyzed by SEM. Fron the experimental data it has been observed that the efficiency of glass fibers has a maximum at a well defined value of fiber content for each polyester foam density. The fracture starts in the matrix, and after a certain amount of fiber debonding fiber fracture occurs. At high fiber contents, there is almost only matrix fracture and fiber debonding.