The determination of the rational parameters of a vibration machine for the internal compaction of concrete mixtures. We researched the “vibration machine – concrete medium” system wherein the concrete medium is represented by a system with distributed parameters that takes into account the resilient, viscous, inertial and energy properties of the compacted concrete medium. We researched the propagation of the viscous-resilient-plastic deformation waves in the contracted concrete mixture represented in the form of a half-space. We determined the amplitudes of the oscillations and stresses occurring in the compacted mixture depending on its physical and mechanical characteristics. We determined the oscillation amplitude of the vibration machine, identified its rational parameters. We determined the regularity of the motion of the compacted mixture and the vibration machine depending on the physical and mathematical characteristics of the compacted mixture, the thickness and width of the compacted layer, the angular oscillation frequency and the amplitude of the exciting force. The presented dependences enable the substantiation of the rational parameters of the vibration machine and the modes of vibratory action.
The objective of the paper is the development of the method for the calculation of the required force of shaping of a horizontal shape-forming machine used in the preproduction workflow. The design of a machine for horizontal shape-forming of wheel steel rims enables quick readjusting and transfer to another rim shape, which is significant under the conditions of frequent alteration of the product nomenclature. We developed the calculation method based on the assumptions of the deformations continuity, the constancy of the volume at plastic deformation and axisymmetric stressed state as well as the local application of the load. The research resulted in obtaining the analytical dependences for the calculation of the force of shaping of a wheel rim, taking into account the degree of deformation, the mechanical characteristics of the metal, hardening as well as the design and technological factors of the process. The topicality of the development consists in the necessity for the high-quality and the least expensive choice of the equipment of the required rated power when designing a new workflow. The experimental data, carried out both under the production and laboratory conditions, confirmed the adequacy of the theoretical formulas. It is determined by the assumptions and solutions obtained based on the mathematical apparatus of the technical theory of the shells of revolution. The clearness of the method will make it possible to algorithmize the calculation process quite easily and to use it as a subprogram in an applied complex of technical preproduction. It will also allow determining the shaping process most significant factors influencing the value of the force without the direct use of the calculation. We recommend to use it at enterprises producing vehicle steel wheels by the method of radial-rotation shaping.
The paper proposes an essentially new design of a concrete mixture depth compactor made in the form of a vertical plate witha circular vibration exciter mounted on its upper part. A design diagram of the «plane depth compactor – concrete mixture»dynamic system is presented and the vertical plate movement equations describing its linear vibrations in the horizontal planeand torsional vibrations in relation to the center of gravity are provided. It has been determined the regularity of the verticalplate motion during the compaction of concrete mixtures. The provided results of the research enable the substantiation of therational parameters of the plane depth compactor performing spatial vibrations and the efficient modes of the vibratory actionon the concrete mixtures of different consistence.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.