Application of Average Stress Criterion to Fracture of Aluminium Alloys Used in Aerospace Applications

Aluminium has been the dominant material in the aircraft industry for a half century due to its attractive combination of light weight, strength, ductility, corrosion resistance, ease of assembly and low cost. This study covers modifications made in one of the stress fracture criteria known as the average stress criterion for accurate prediction of notched tensile strength of aluminium alloy specimen used in aerospace applications. To examine the adequacy of these modifications, fracture data for centre-cracked 2XXX, 6XXX and 7XXX aluminium alloy specimens are considered. The notched (fracture) strength estimates are found to be close to the test results. The modified average stress criterion proves to be a very simple method to predict the notched tensile strength.