Experimental evaluation of J-integral in elastic and elastic–plastic polymers by means of digital image correlation and higher-order eigenfields under mode-I

Abstract

This study examines the capability of the digital image correlation method to determine the J-integral for polymers with elastic and elastic–plastic behavior. To achieve this, the required analytical concepts are discussed in detail and single-edge notch tension specimens manufactured out of PMMA and HDPE are tested under pure mode I loading conditions. Three specimens of each material are tested under different loads, and the displacement field at the surface of each specimen is obtained using DIC. Using the least square method, the displacement field derived by DIC is used to determine the higher-order singular and non-singular terms of the Williams expansion. The J-integral for each specimen is then computed by combining these terms. In addition, the J-integral obtained by DIC is compared to that derived by finite element analysis, and an excellent correlation is observed. Lastly, the influence of different DIC parameters on the computed results is discussed.