Test MethodDevelopment of SENB toughness measurement for thermoset resins

Conventional single-edge notched bending (SENB) fracture toughness measurement is ideal for plastic materials, but it is intrinsically difficult to initiate a sufficiently sharp crack for brittle thermoset resins. The problem was addressed in this research by an instantly propagated crack with a geometry-modified SENB specimen. Because the crack sharpness was natural, sufficient and repeatable, the obtained toughness value was accurate and reproducible, which was verified by double cantilever beam and compact tension measurements. The methodology developed here will provide a guide for brittle thermoset toughness testing.