The SB (Sandwiched Beam) Technique for Pre-Cracking Brittle Materials
The SB (sandwiched beam) methodology to introduce sharp through-thickness defects in brittle materials is described in this work. A notched bar is inserted between two support beams and the obtained sandwich is loaded in bending. In this configuration a crack can grow from the notch tip in a stable and controlled way, if appropriate experimental conditions are used. The obtained defects are suitable to measure fracture toughness; in fact, they are geometrically well defined and they are not associated to residual stress field. In addition it is possible to obtain cracks of different length that allow the evaluation of eventual toughening effects.
KeywordsFracture Toughness Stress Intensity Factor Strain Energy Release Short Crack Sandwich Beam
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