Damage accumulation in aluminum alloys under plastic deformation and creep

The accumulation of local and bulk damage in D16 AT and 1201 T1 aluminum alloys used in aircraft engineering is studied. The local damage level is calculated from data of thermoactivation analysis of the residual life of D16 AT alloy specimens after preliminary plastic deformation. The bulk damage level is determined from the elastic-modulus defect by measuring the natural frequency of 1201 T1 alloy specimens. Life tests of the specimens were performed at constant tensile loads and elevated temperatures. The dependence of the local damage on preliminary plastic strain at room temperature is obtained. The residual life of the specimens is calculated with allowance for the damage to the material in the initial stage of failure and compared with experimental results. Data are given on the kinetics of bulk-damage accumulation in various test regimes.