Composite materials meet many needs in a wide variety of applications. Their unique properties enable them to provide solutions where other materials cannot compete. The complexity of polymeric composite materials makes characterization of their mechanical properties challenging. There are many standard tests to help in interrogating composite materials. There are ASTM, ISO, and other standards to guide testing, and care must be taken to choose the right tests for your applications. This means paying careful attention to loadings and environmental conditions including temperature and humidity. Imparting the pertinent stresses to your composite materials may involve biaxial testing. This review of strain measurement methods with advantages and disadvantages of each includes strain gages and a variety of extensometers.
Written by: Brent Larson