Effect of Blunt Notches and Saw Cuts on the Static Strength of 2024-T3 and 7075-T6 Sheet Material

摘要

The effect of holes on the static strength of aluminum alloy sheets used in aircraft was tested. Sheet specimens with circular holes and slotted holes to cover a Kt range from 2 to 5, with notch root radius 2 or 5 mm were produced. The effect of the notches on the static net section failure stress is small, involving an average reduction at Kt = 3 of 8% and 1% for 2024-T3 and 7075-T6 respectively. The trends observed can be understood qualitatively from plasticity considerations. For saw cuts, the failure stress corresponds to net section yield for the 2024-T3 alloy, while for 7075-T6 a modified Feddersen diagram represents the results quite well.