Determining tab material for tensile test of CFRP laminates with combined usage of digital image correlation and acoustic emission techniques

Determining the precise tensile strength of carbon fiber reinforced polymer matrix composites is very important due to their anisotropic properties. In this study, tensile tests are carried out on carbon fiber reinforced laminates with glass and carbon fiber reinforced tab materials. Tests are conducted with concurrent monitoring of mechanical behavior of specimens through digital image correlation and acoustic emission techniques. Remarkably, the full field strain maps obtained through digital image correlation show that there is a relationship between uniformity of strain field at gauge length and tab material used for tensile tests. Three distinct stages of acoustic emission activity are determined, in which the duration of second stage changes significantly depending on the tab material used for tensile test. Finally, the experimental tests are numerically simulated through the finite element method in conjunction with a progressive damage analysis. A good agreement between the numerical and experimental results is obtained.