Calculation of plates made of strain-hardening material with different resistance to tension and compression under creep

Samples cut from AK4-1T alloy plates with thickness h = 45 mm are experimentally investigated at T = 195 degrees C under tension and compression conditions. The alloy is strain-hardening and has different resistance to tension and compression under creep. Constants for power-law dependences describing creep strain rates are defined according to the experimental data. The model based on the "transformed" space of stresses, taking into account properties of hardening and different resistance of material to tension and compression at creep is developed. The model is tested for the problem of AK4-1T alloy plates' pure torsion in assuming of planes stress-strain state. Experimental data on flexible plates' torsion and finite elements' calculation in geometrically nonlinear statement using constants only on tension or compression are presented. Experimental values are located between the relevant calculated lines, that confirms the complex properties of alloy. These properties should be taken into account in the calculations.