scholarly journals DETERMINING THE BALANCE CONFIGURATION, IN CASE OF THE OSCILLATING MOVEMENT OF THE MAIN SPINDLE AT CNC LATHE

Author(s):  
Daniel Popescu

In the paper we present a mathematical model through which are determined the balance conditions, needed for the stability analysis of the oscillating movement of the main spindle at CNC lathe. We take into account Hamilton's variation principle, the axiom of impulse derivative and the axiom of kinetic moment derivative. We present the general movement equations that generate the oscillations based on the calculus hypotheses, performing the introduction of the external solicitations. Establishment of the balance configuration is done by imposing the conditions that the system of forces that act upon the ensemble spindle – bearings - tool causes a deformation of the spindle, without producing spindle vibration. We obtain the new differential equations of the movement, in which the forces and moments are determined from the static case, based on which we can determine the integration constants in the characteristic points of the main spindle.

Author(s):  
Daniel Popescu

In the paper we present a mathematical model through which are determined the balance conditions, needed for the stability analysis of the oscillating movement of the main spindle at CNC lathe. We take into account Hamilton's variation principle, the axiom of impulse derivative and the axiom of kinetic moment derivative. We present the general movement equations that generate the oscillations based on the calculus hypotheses, performing the introduction of the external solicitations. Establishment of the balance configuration is done by imposing the conditions that the system of forces that act upon the ensemble spindle – bearings - tool causes a deformation of the spindle, without producing spindle vibration. We obtain the new differential equations of the movement, in which the forces and moments are determined from the static case, based on which we can determine the integration constants in the characteristic points of the main spindle.


Author(s):  
POPESCU DANIEL

The paper presents a mathematical model for determining the movement equations that generate the transversal vibration of the main spindle at CNC lathe. For this purpose, we take into account the general equations which generate the vibration of the spindle, obtained by means of Hamilton’s Variational Principle as well as the impulse derivative and kinetic moment axioms. The solutions to the movement equations are arranged under the form of a system of first order partial derivatives equations, for which we determine the integration constants. This original way of establishing these equations allows further analysis of the main spindle vibrations in transversal direction and finding ways to decrease the vibration amplitude.


2018 ◽  
Vol 33 ◽  
pp. 02063 ◽  
Author(s):  
Andrey Aksenov ◽  
Anna Malysheva

The analytical solution of one of the urgent problems of modern hydromechanics and heat engineering about the distribution of gas and liquid phases along the channel cross-section, the thickness of the annular layer and their connection with the mass content of the gas phase in the gas-liquid flow is given in the paper.The analytical method is based on the fundamental laws of theoretical mechanics and thermophysics on the minimum of energy dissipation and the minimum rate of increase in the system entropy, which determine the stability of stationary states and processes. Obtained dependencies disclose the physical laws of the motion of two-phase media and can be used in hydraulic calculations during the design and operation of refrigeration and air conditioning systems.


2019 ◽  
Vol 16 (11) ◽  
pp. 1950170
Author(s):  
H. Nazar ◽  
G. Abbas

In this study, we analyze the complexity factor that is extended up to the dynamical spherically symmetric non-static case with anisotropic dissipative self-gravitating fluid distribution in context of [Formula: see text] theory of gravity. For this evaluation we choose the particular [Formula: see text] model that signifies the physical nature of the self-gravitating system. The proposed work discusses not only the complexity factor of the structure of the fluid distribution, but also defines the minimization rate of complexity of the pattern of evolution. Here, first we have applied similar approach for obtaining the structure scalar [Formula: see text] of the complexity factor as used for in the static case, and next we have described explicitly the dissipative and non-dissipative cases by assuming the simplest pattern of evolution (homologous condition). It has been found that the system configuration fulfills the vanishing condition of complexity factor and emerging homologously, corresponds to a energy density homogeneity, shearfree and geodesic, isotropic in pressure. Moreover, we define the stability results for the vanishing complexity factor condition. Finally, we would like to mention that these results are satisfying the prior investigation about complexity factor in General Relativity (GR) by setting [Formula: see text].


2012 ◽  
Vol 590 ◽  
pp. 465-470
Author(s):  
Zhi Wei Zhang ◽  
Song Li ◽  
Bing Bing Chen ◽  
Jin Chun Song

According to the testing craft and requirements of CNC Lathe about main spindle box, testing system of hardware and software structure was designed in this paper. It adopts sensors, data acquisition cards, industrial control computer, frequency converter and so on as hardware, good data analysis methods, and LabVIEW as software tool, to realize real-time monitoring of main spindle box testing conditions.


1962 ◽  
Vol 2 (3) ◽  
pp. 357-368 ◽  
Author(s):  
J. M. Blatt ◽  
J. N. Lyness

AbstractContrary to the general impression that variation principles are of purely theoretical interest, we show by means of examples that they can lead to considerable practical advantages in the solution of non-linear vibration problems. In this paper, we develop a variation principle for the period of a free oscillation, as a function of the average value of the Lagrangian over one period. Even extremely simple-minded approximations to the true motion lead to excellent values for the period. The stability of such free oscillations against small disturbances of the initial conditions is treated in a previous paper.


2020 ◽  
Vol 19 (3) ◽  
pp. 0018
Author(s):  
Duaa Awadh Dr. Bushra Kadhum

 The scientific progress made in sport in the world did not come as a result of chance but rather by relying on training and educational means based on sound scientific foundations in the individual and individual games, as gymnastics is one of the sports that contain several movements and at the same time these movements may be performed in One movement of the gymnastics. The player who plays this game must be characterized by good physical and skill specifications, as any defect in it affects the player's skill performance and thus his achievement is not good and this affects progress towards achieving what he aims. And that the general motor balance is an important pillar in the performance of any movement of the gymnast and that the player who is characterized by the stability of the balance will be easier to learn unlike the one who has a weakness in the general balance is learning more difficult and therefore can not achieve what he aims to accomplish, especially if he did not discover Early. Hence the importance of the research to improve the weakness of the general motor balance when performing the skill of the forward anterior heart, by developing exercises that improve the performance weakness. Hence, the researcher sought to solve the problem. The weak general movement balance among the players of the technical gymnastics resulted from the lack of interest Adequate motor balance in performance or physical numbers, which plays an important and effective role in improving performance significantly, and because balance is an important skill trait in the game of gymnastics and that its weakness may not only affect learning the skill of the frontal air ball developed, but rather achievement in general, The prompting the researchers to study the problem and develop special exercises to help improve weak balance when motor performance and find the best solutions to scientific even have to be a good player. The third chapter includes the research sample community and sample for the sub-union players of your gymnasium in Maysan for junior athletes, ages (10-13) years, they are (6) young players. As for the fourth chapter, the results are presented, analyzed and discussed. As for the fifth chapter, it includes conclusions and recommendations, including the conclusions: The effect of the exercises was positive in developing physical and motor abilities. The development of physical and motor abilities through exercises led to the learning of free skills in technical gymnastics as well as balance. As for the recommendations Trying to improve the performance of the basic skills in your technical gymnastics while giving other motor skills for the older age group for the purpose of learning them and benefiting from them in performing compulsory motor formations.


2013 ◽  
Vol 671-674 ◽  
pp. 1561-1569
Author(s):  
Yan Li Wang ◽  
Guang Hui Qing

Firstly, based on the theory of state-vector equation, the semi-analysis finite element formulation for the stability of the plates under various boundary conditions was derived by modified Hellinger-Reissner (H-R) variation principle for the elastic material. Secondly, the three-dimensional models for the stability of stiffened plates were established. The semi-analytical solution of state equation for the stability of stiffened plates are proved to be efficient and accurate by comparing with the exact solutions of references and the numerical solutions of the finite element software through several examples.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Yawei Han ◽  
Shuai Guo ◽  
Leigang Zhang ◽  
Fengfeng (Jeff) Xi ◽  
Weiwei Lu

Discussed in this paper is the tip-over stability analysis of a pelvic support walking robot. To improve the activities of daily living (ADL) in hemiplegic patients, a pelvic support walking robot is proposed to help patients facilitating their rehabilitation. During the gait training with the robot, the abnormal man-machine interaction forces may lead to the tip-over of the robot, which is not beneficial to the rehabilitation process. A new method is proposed to predict the possibility of tipping over and evaluate the stability of the robot based on statics model, dynamics model, and zero-moment point (ZMP) theory. Through the interaction forces and moments analysis with static case, the safe point (ZMP) is studied, and the influence factors of force/moment are analyzed by dynamics case. An optimization algorithm based on the genetic algorithm (GA) is proposed to reduce the risk of tipping over. The simulation results show that the optimization algorithm can keep the robot from tipping over when the interaction forces exceed the safety threshold.


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