Determining the influence of continuous section shape and dimensions on stresses over a wide range of vibration frequency

Abstract

Problem statement. Considering the prospects of using discrete-continuous vibration machines, there is a need to study the properties of continuous sections, which are elastic plates, in a wide range of frequencies. Purpose. It consists of studying the frequency response of continuous sections of various shapes and sizes from the harmonic disturbance force and identifying the frequency ranges in which the maximum stresses will be observed. Methodology. A schematic diagram of a discrete-continuous oscillating system is given. A set of necessary parameters is selected, which the studied samples of continuous sections should possess. Rectangular, diamondshaped, X-shaped, parabolic convex and parabolic convex plates of different thicknesses corresponding to the given parameters were designed. Control point arrays were selected to investigate stresses in the plates. For each of the plates, a linear dynamic analysis was carried out with the help of simulation modeling. The dependence of the maximum stresses at the control points of the investigated plates on the frequency of the harmonic disturbance was determined. Findings (results) and originality (novelty). A linear dynamic analysis of continuous sections of various shapes and thicknesses was performed for the first time. The results obtained from the conducted research, in general, indicate the presence of stress amplifications occurring in plates of various shapes and sizes at certain frequencies of harmonic disturbance. In all investigated types of plates, stress amplifycation was found at the first and third natural frequencies of oscillations. It was determined that the largest stresses occur in the parabolic convex plate and the smallest – in the parabolic convex. Practical value. Frequency ranges have been established in which, with harmonic disturbance of continuous sections, it is possible to obtain significant dynamic amplification of oscillations of discrete-continuous vibrating machines with an electromagnetic drive. Recommendations for choosing the optimal geometric parameters of the plates as continuous sections of vibration machines, in which they could be operated for an infinite number of load cycles, are described. Scopes of further investigations. The reaction of continuous sections with various shapes and dimensions to the simultaneous interaction of several forces with different frequencies and amplitudes of disturbance requires further research.