METHOD OF FATIGUE CRACKS INHIBITION AND OCCURRENCE PREVENTION Russian patent published in 2018 - IPC E01D22/00 

FIELD: building of bridges.

SUBSTANCE: method relates to the field of bridges construction and can be used for the fatigue cracks occurrence prevention and development inhibition in the walls of the bridges span structures main metal beams and the span structures roadway section longitudinal beams. Effect of the crack inhibition in the bridges span structures metal element is achieved by the compressive stresses and structural barrier creating along the crack development path, for this, on the beam wall one side at the crack tip, performing the local zone with diameter of 50 mm induction heating over the entire wall thickness to the temperature of 800–850 °C; simultaneously with heating after reaching the heating temperature of 750 °C on the beam wall other side, performing the zone with diameter of 30 mm mechanical forging near the crack mouth using the electromechanical or pneumatic tool with a round striker. After the operation performance on one side, it is repeated on the beam wall other side. Beam wall local heating in the crack zone partially removes the residual stress fields near the crack, which reduces the probability of further crack propagation along the wall metal. Induction heating of the zone along the crack development path not only creates the compressive stresses zone, but also allows to produce forging (create a plastic deformations zone preventing the crack development) to a much greater depth than with the high-frequency mechanical forging.

EFFECT: method allows to slow down further growth of crack at an early stage of its appearance.

1 cl, 3 dwg