Determining the rheological properties of viscoelastic materials by the values of creep strain

Determination of creep strain arising due to stresses acting up to the moment of time t is considered. The phenomenon of constant-stress creep is described. A method is proposed to determine the parameters of the Arutyunyan creep kernel selected to describe the behavior of a material using two creep curves of a material with viscoelastic properties and nonlinear dependence of creep strain on the stress. In addition, the constant in the expression describing nonlinear dependence of creep strain on the stress is defined. The AMg6M alloy, widely used in the design of aerospace products, was chosen as the material to be analyzed. The tests were carried out on samples 3 mm thick at strains of 65 MPa and 156.9 MPa. According to the results of testing samples of materials on the test bench of Samara University creep curves were obtained. By determining the parameters of the approximation of the Arutyunyan kernel and the parameter included in the expression of nonlinear dependence of creep strain on the stress, it is possible to determine the value of the creep strain of the material for arbitrary values of stress and time. Comparison of the experimental and calculated creep curves for the AMg6M alloy confirms the validity of determination of the rheological characteristics of the tested material.