Mode II – Measurement in an SENB/ENF Test Arrangement
Mode II loading can be applied and measured in a flexure test and in a tensile and compression test with notched specimens.
Measurement of the Mode II energy release rate is standardized as a flexure test. Shear stresses arising in the flexure test are used to propagate the crack. The specimens are denoted with SENB (single end notch bending), but ENF (end notch flexure) is also term commonly used. Deflection is measured via the crosshead travel (with correction for stiffness) or using a displacement transducer centrically attached.
The crack initiation point is characterized by a maximum force. At the end of mesurement, the specimen is cooled in liquid nitrogen and then completely broken to measure the fracture surfaces.