Auxiliary tool for improving fracture toughness testing precision of aluminum alloy sheet

The invention relates to an auxiliary tool for improving fracture toughness testing precision of an aluminum alloy sheet. The auxiliary tool comprises anti-warping Z-shaped plates and movable handles. One end of each movable handle is mounted on the corresponding anti-warping Z-shaped plate, and the other ends of the movable handles vertically penetrate through fixed supports. Sliding supporting rods are perpendicular to the movable handles and penetrate through the fixed supports. The four anti-warping Z-shaped plates are mounted and assembled in a rectangular mode for use. A rectangular groove is formed in the center of one face of each anti-warping Z-shaped plate, two movable handles perpendicular to the center axis of each anti-warping Z-shaped plate are symmetrically arranged on the other face of the anti-warping Z-shaped plate, and the other ends of the two movable handles penetrate through the two fixed supports. The sliding supporting rods penetrate through the two fixed supports in the direction perp