Methods of reducing the negative impact of resonant oscillations on the quality of concrete products during their vibration compaction

Abstract

Problem. Most of the equipment for vibroforming of concrete in the production of concrete construction products uses a "over-resonant" mode of operation. The system goes through resonance during acceleration and also before a complete stop. This is detrimental to the products, as newly formed products suffer from resonant oscillations. Goal. The goal of the research was to investigate ways to reduce the negative impact of negative resonance oscillations on products by reducing the time spent in the resonance mode and reducing the amplitude of oscillations. Methodology. The computational and analytical method of finding dependence, a comparative analysis of engine designs and experimental strain-metric studies of two designs of vibration platforms were applied. Results. The value of the angle forming the sector unbalance is substantiated both for the variant without the hub on the unbalance and with it. From the standpoint of minimizing the moment of inertia of the rotor, the expediency and perspective of using a hydraulic motor instead of an electric asynchronous motor has been proven. Other advantages of the hydraulic motor over the electric motor for vibrating machines and vibropresses with frequent transient processes (start-stop) are substantiated. It has been proven that the use of rubber elastic elements instead of steel springs in systems with frequent transient processes may be more appropriate. The amplitude of resonant oscillations in a vibration system with rubber elastic elements is smaller, and the transition through resonance occurs faster. Originality. Ways to reduce the negative impact due to resonance are considered comprehensively. Vibration studies were performed on two vibration platforms with different types of elastic elements. Practical value. Reducing the intensity and duration of resonant oscillations in over-resonant technological equipment for forming building products will positively affect the quality of products. The application of the proposed design features will improve the working conditions of workers and the reliability of equipment.