Abstract
Researched initiation and propagation of short surfaces fatigue cracks out of open in double-sided botch laminated sheet of aviation aluminum alloy 2024-T3 at stable amplitude one-sided bend (R=0.1). Research of the initial stage of development of cracks is realized by use of a SEM microscope, and it allowed to set the place of origin of crack and mikromechanisms of fracture of aluminum sheets, and also type of front of crack. Established a large enough scatter of velocity of propagation in the area of development of short cracks, which for a sheet from this alloy, with a thickness of 3 mm, reaches 0.5 mm. On the basis of fractografy researches modified model of analytical description of propagation of short fatigue crack is proposed.