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Solving as an example the plane problem of the mechanics of a rod strip having a fixed finite-length section on one of its front surfaces, we have shown that when studying deformation processes with consideration of the compliance of the fixed section, it is necessary to take into account the change in the stress–strain parameters and the mathematical models used for their description. This change occurs across the boundary between the unfixed and fixed sections. Within the framework of the classical Kirchhoff–Love model, it is impossible to take into account the compliance of the fixed section of the rod. However, within the framework of the refined Timoshenko shear model, this is possible if the section is fixed only on one of the front surfaces. Exact analytical solutions were found for two simple linear problems of static transverse bending of a flat rod with fixed sections of finite length on one of the front surfaces. One-dimensional finite elements were constructed for modeling unfixed sections of flat rods and sections fixed on one of the front surfaces within the framework of the refined Timoshenko shear model. Numerical experiments were performed, showing the necessity of taking into account the change in the rod strain-stress parameters across the boundary between fixed and unfixed sections. [ABSTRACT FROM AUTHOR]

Theoretical-experimental method is proposed in this paper for determining the logarithmic decrement of vibrations based on the measurement of tip amplitude of the flat cantilever test samples during their damped vibrations at first resonance mode. Significant effect of external aerodynamic forces on logarithmic decrement is observed. Extensive theoretical and experimental studies were performed on the aerodynamic component of damping of oscillated flat strip plates. For the assessment of its contribution to overall damping of test samples during their free vibrations, large number of numerical experiments were carried out on two dimensional flow dynamics around the plate, in the light of which an approximated empirical formula is found. Present study is also covering the method to identify the elastic properties and amplitude dependencies of logarithmic decrement on deformation in accordance with the data of physical experiments performed with various series of test samples. [ABSTRACT FROM AUTHOR]