Characterisation of Crack Propagation in Natural Rubber Under Complex Loading Conditions Using Thermographic Methods

The present work describes the formation and propagation of double cracks in elastomer materials under complex multiaxial loading. Mechanical measurements are complemented by optical measurements to determine local strain fields and thermal measurements to detect local temperature changes and energy dissipation in the material, respectively. The results are applied to analyse the crack growth behaviour in the case of double cracks and compared with the classical method of Rivlin and Thomas (J Polym Sci 3:291–318, 1952), with which they show good agreement. As material a natural rubber, loaded with 20 phr carbon black, is used. The experiments were performed on a biaxial testing machine using an optical digital image correlation system to measure the local strain. Simultaneously, the thermal behaviour was determined by infrared thermography.