Modification of simple deformation processes of metallic materials by means of cyclic loading

Abstract

The paper presents experimental results concerning evaluation of an influence of cyclic loading on material behaviour under monotonic deformation. Tests were carried out on pure copper and P91 steel. The experimental programme contained the torsion–reverse–torsion cycles superimposed on the monotonic tension. It is shown that the torsion–reverse–torsion cycles associated with monotonic tension caused essential variations of the tensile characteristic. For both materials, a significant decrease in the tensile stress can be observed. The effects observed during monotonic and cyclic loading combinations were theoretically described for the 2024 aluminium alloy using the Mróz and Maciejewski model.

Keywords:

• Complex loading
• Yield point
• Yield surface
• Mechanical parameters

The support from the Ministry of Science and Higher Education (Poland) under grant no. N N501 121 036 is greatly appreciated.