ANALYSIS OF AMPLITUDE-DEPENDENT DAMPING AND ITS APPLICATION IN NUMERICAL CALCULATIONS.

Digital twins are becoming an essential part of the product designing. In the rocket and space technology, a dynamic finite element model represents the important component of the digital twin. This model is required to be capable of predicting behavior of the structure under dynamic load with a reliable accuracy. At the same time, calculations of the design response with allowance for amplitude- dependent damping are impossible by the modern finite element software. This article presents the test results of flat aluminum alloy samples which are the time characteristics of free damped oscillations and amplitude- frequency characteristics of forced oscillations of samples. An analysis of test results was carried out using the existing methods for obtaining dependences of the dumping on the equivalent (von Mises) stress in the material. The paper describes a damping matrix formation for numerical calculations using constant damping coefficients. Also, the article proposes an iterative algorithm, which enables the application of amplitude- dependent damping coefficients in the harmonic analysis.