Bending Specimen for Producing Crack without Sudden Fracture and Method for Producing Bending Crack in such Bending Specimen

摘要

The present invention relates to a ″bending test piece″ with various sizes of bending cracks with a specific width and depth desired by a user, which are artificially generated in advance, and a ″manufacturing method of the bending test piece.″ According to the present invention, the bending test piece is a sample, that is, a ″bending test piece″ in a shape of a beam, which has a rectangular cross-section and is extended long in a longitudinal direction, applying a vertical load to cause a bending behavior, and to generate the bending cracks in advance without a sudden splitting. According to the present invention, the manufacturing method thereof, which manufactures the bending test piece (100) by using a mold manufactured in the shape of a rectangular parallelepiped, comprises: a step of manufacturing the bending test piece (100) to have a penetrating hole (1) for preventing a crack from spreading; a step of applying a vertical load vertically at a position where the penetrating hole (1) for preventing a crack from spreading exists; and a step of, when the bending cracks (3) reach a specific width and depth desired by the user, eliminating the vertical load. Accordingly, the present invention is able to block a phenomenon where bending cracks are spread up to an upper surface of the bending test piece by the penetrating hole (1) for preventing the cracks from spreading, and to manufacture the bending test piece with the bending cracks with the width and depth in a size desired by the tester, which are formed in advance, while keeping the status of the bending test piece being not separated by suddenly splitting.