Identification of the Dynamic Elasticity Characteristics and Damping Properties of the OT-4 Titanium Alloy Based on Study of Damping Flexural Vibrations of the Test Specimens

Аннотация

This article shows the significant decrease in the dynamic elasticity modulus of the OT-4 titanium alloy within the frequency range of 0–25 Hz as compared with the static elasticity modulus with further stabilization of the mentioned dynamic modulus at 25–80 Hz based on study of the damping flexural vibrations of the cantilevered test specimens. The procedure of identification of the damping properties of the mentioned alloy during expansion-compression, with account of the internal and external aerodynamic damping based on the finite element method and minimization of the target function containing the experimental and calculated logarithmic vibration decrements of the test specimen, was developed. The matrix of aerodynamic damping of the finite element, on the basis of the Morison approximation aimed at conceptualization of the force per unit length of the aerodynamic resistance during vibration of the test specimen, was made. The averaged amplitude dependence of the logarithmic vibration decrement presenting the damping properties of the investigated OT-4 alloy was obtained by several test specimens.