ABSTRACT: This article examines one of the most important strokes in tennis sport, namely, service strokes. The study covers three types of strokes: flat, slice and kick service strokes. A specially made program has been compiled in the area of MatLab, with the help of which the strongly nonlinear differential equations are integrated. These equations …
A27: Study the Service Strokes in Professional Tennis Read More »
ABSTRACT: The article considers the impact interaction of a railway vehicle with a fixed barrier. The movement of the vehicle is carried out at different velocities. A dynamic model of a buffer is offered, which includes an elastic element, a damper, and a friction mechanism. The elastic element has a nonlinear characteristic. The damper is …
A26: Impact Interaction of a Railway Vehicle with a Fixed Barrier Read More »
ABSTRACT: Bipolar Plates (BPPs) are the most crucial component of the Polymer Electrolyte Membrane (PEM) fuel cell system. To improve fuel cell stack performance and lifetime, corrosion resistance and Interfacial Contact Resistance (ICR) enhancement are two essential factors for metallic BPPs. One of the most effective methods to achieve this purpose is adding a thin …
ABSTRACT: Modern tennis sport is characterized by constant change in several directions. The most significant of these changes are connected to the design of tennis rackets. The composite material of the rocket’s frame is continuously improved. It is also working hard on improving the tennis strings. Tennis balls are also being modified. All these innovations …
ABSTRACT: The oscillations of a pendulum suspended on an elastic beam are examined. The mathematical pendulum is a material point suspended on an ideal rigid and massless rod. The upper end of the rod is connected by a joint with an elastic beam on two supports. The beam is considered to be perfectly elastic and …
ABSTRACT: Modern tennis players use a variety of strokes. From the physical point of view, these shots can be classified into eight main groups depending on the way the racket interacts with the tennis ball. These are strokes with top, bottom, side, top-side, and bottom-side rotation, as well as strokes without rotation. These eight interactions …
ABSTRACT: The article examines the three-dimensional vibrations of an elliptical disk. It is rigidly connected to a horizontal cylindrical shaft. The normal axis to the plane of the disk makes an acute angle with the axis of the shaft. The shaft is considered to be a cylindrical perfectly elastic and weightless rod with stiffness of …
A21: Vibrations of Elliptical Disc from Inertial Excitations Read More »
ABSTRACT: The purpose of the study is to examine the adaptation of coal mining enterprises to the requirements of the Climate Agenda and the prospects for a low-carbon future in the Kuzbass region. The subject of the research is the impact of coal mining on the conservation of the region’s biocapacity and the future “green” …
A20: Low-Carbon Development of Kuzbass: Coal Mining and Land Reclamation Read More »
ABSTRACT: The purpose of the study is to examine the issues of assessing the anthropogenic impact on the ecosystem and sustainable development of a region using the example of Kuzbass. The subject of the study is to substantiate the need to improve the measurements of sustainable development of the regional economy from the point of …
A19: Ecological Footprint and Decoupling in the Sustainable Development of a Region Read More »
ABSTRACT: Small vibrations of a cylindrical shaft caused by inertial excitations are studied in this paper. The shaft is vertically situated. It consists of two sections with different cross sections. It is supported by a spherical and a cylindrical joint. The two supporting devices have horizontal elasticity. Between the two supports, and also at the …
A18: Vibrations of Shaft Caused by Inertial Excitations Read More »
ABSTRACT: In this article, new equations called Condensed Lagrange equations (CLEs) are defined. With their help, the rigid body’s absolute general motion is studied. The rigid body is considered to be homogeneous and unsymmetrical. CLEs are similar in structure to the classical Lagrange equations from the second type, applied in vector-matrix form, but CLEs are …
A17: Condensed Lagrange Equations in Theoretical Mechanics Read More »
ABSTRACT: In this article, a rigid body’s absolute general motion is studied. The rigid body is assumed as homogeneous and unsymmetrical. New additional kinetic characteristics are used. The most important of these are the following: the vector-real generalized velocity of the rigid body, the vector generalized impulse of the rigid body, and the vector-real generalized …
A16: Theorem for Change of Generalized Impulse in Theoretical Mechanics Read More »
ABSTRACT: The absolute motion of an arbitrary asymmetric rigid body is studied. This motion is determined after its relative motion has been obtained. The most important peculiarity in this dynamical rigid body model is that the selected pole does not coincide with its mass center. Seven new kinematic characteristics have been defined. The first ones …
A15: Theoretical Matrix Study of Rigid Body Absolute Motion Read More »
ABSTRACT: The relative motion of an arbitrary asymmetrical rigid body in this article is studied. Three new additional kinematic characteristics are defined, namely, vectors-real absolute, transmissive, and relative generalized velocity. A new theorem for summation of the rigid body’s real generalized velocities, with these new additional kinematic characteristics, is formulated. Using the final differential equations …
A14: Theoretical Matrix Study of Rigid Body Relative Motion Read More »
ABSTRACT: In this paper, the trajectories of a soccer ball for the most important kicks in the football game – a corner kick and a direct free kick are studied. The soccer ball is modeled as an ideal rigid hollow spherical body with six degrees of freedom, which performs a general motion in an immovable …
ABSTRACT: The forced three-dimensional vibrations of a machine unit “electric motor-compressor”, mounted on the wagons of electric trains from the traction of “BDZ” EAD in this work are studied. The purpose of the work is to determine the parameters of the vibrating insulation of the unit that is suspended on three vertical supports to the …
ABSTRACT: In this paper, the forced three-dimensional vibrations of a machine unit mounted on the wagons of the electric modular trains are studied. The unit is suspended on three vertical supports to the wagon frame. A vibrating isolation assembly is constructed at the top end of each carrier. The unit is accepted as an ideal …
ABSTRACT: Vibrations resulting from powertrain work and auxiliary equipment reduce the comfort, reliability, and durability of the vehicles. The vibration levels transmitted to the passenger compartment and the emitted structural noise depend mainly on the efficiency of their vibration isolation with respect to the vehicle body. The work presents an experimental determination of the vibration …
A10: Experimental Determination of Vibration Levels of Electric Compressor Aggregate Read More »
ABSTRACT: The article examines the general motion of a homogeneous solid body in a fluid medium. The body is an ellipsoid with three mutually perpendicular planes of geometric and material symmetry. The intersections of these planes with the ellipsoid represent three ellipses of different sizes. The body is assumed to have six degrees of freedom. …
ABSTRACT: The article examines the general motion of an arbitrarily asymmetric homogeneous rigid body in a fluid medium. Through a defined new theorem – Theorem for change of the generalized momentum of a rigid body, and new Lagrange equations in structure, called Condensed Lagrange equations, the differential equations describing the spatial movement of the body …
A08: Motion of Asymmetrical Rigid Body in Fluid Area Read More »
