FRACTURE PARAMETER EXTRACTION FROM DIC DISPLACEMENT FIELD IN EPOXIES

Compact tension (CT) specimens of two different toughened epoxies were tested to failure and digital image correlation displacement fields recorded. K-I and T-stress values were extracted from the data using the Williams stress solutions and compared with theoretical values. Experimental complexities and difficulties are discussed. Directly extracted stress intensity factor results were shown to be within 1% of theoretical values. Validating T-stress measurements was found to be difficult but measured values are in an expected range and finite element studies are being carried out to validate them.