Failure Properties and Phenomena for Zircaloy-4 from Ring Compression Testing

An effective method to determine the plastic strain at fracture and investigate the fracture energy of as-received and hydrided unirradiated Zircaloy-4 tubes in the hoop direction at room temperature was developed for ring compression tests through experimental and computational evaluation. The hydrogen content was varied up to 610 weight parts per million so that failure was consistently ductile. A Gurson-based approach for ductile damage was used to model material failure. Experimental test results and computational simulations modeled in Abaqus were integrated to directly determine plastic strain at fracture, and empirical fitting was used to investigate fracture energy. As expected, increasing hydrogen content caused embrittlement of the Zircaloy-4 samples tested and the plastic strain at fracture and fracture energy to decrease. The developed procedure was demonstrated to directly determine plastic strain at failure and indirectly evaluate comparative fracture energies.