Evaluation of the effects of cross-linking and swelling on the mechanical behaviors of hydrogels using the digital image correlation method

Experimental evaluation and modeling are important steps in the investigation of the mechanical behaviors of hydrogels in the small- to large-strain range. In this study, the effects of cross-linking and swelling on the true stress–strain response of a specific type of hydrogel (polyacrylamide) were evaluated using a uniaxial tensile test. The development of true strain on the surface of the hydrogel was measured using the digital image correlation method. The specimens with higher cross-link density exhibited a higher initial elastic modulus and earlier orientation hardening....