摘要：During exploitation the materials of constructionsstart gradually accumulate the damage, which finallycauses fracture of the construction. The accumulation ofdamage occurs as a result of the high cycle and low cycledamage due to the cyclic overloads, which cause the elas-tic-plastic deformation. Especially dangerous is the over-load as cyclically varying stresses exceed the proportionallimit of the material and plastic strain starts, which resultsthe hysteresis loop of the plastic strain and causes the re-duction in material fatigue life up to thousands or hundredscycles. It is defined that 75% of fracture of the mechanicalsystems’ constructions occurs due to material fatigue [1 -6].
