Determination of characteristics of damping capacity for rods formed from several materials oscillating at different amplitudes and frequencies

Abstract

Results of experimental study of the damping capacity of steel St. 3, glass-cloth-base laminate VFT-S, and beech wood by the method of damping oscillations during the transverse oscillations of cantilevered prismatic specimens within a broad range of stress amplitudes and vibration frequencies are presented. The experiments were conducted on the first three forms of transverse rod oscillations. Variation in vibration frequency was achieved by successive shortening of the specimens. An amplitude dependence of the logarithmic vibration decrement, which was adopted as a characteristic of the damping capacity, was obtained for all materials tested. The influence exerted by vibration frequency on the magnitude of the vibration decrement in the frequency range under consideration is established for specimens formed from the glass-cloth-base laminate VFT-S and beech wood, and is virtually undetected for steel St. 3 specimens. Empirical expressions that make it possible to describe the frequency dependencies of the vibration decrement of the materials under investigation with allowance for stress amplitude are proposed.