scholarly journals Simulation of radial oscillations of a spring-loaded roll in a roll compactor

2021 ◽  
Vol 65 (6) ◽  
pp. 742-748
Author(s):  
S. A. Chizhik ◽  
O. M. Volchek ◽  
V. Y. Prushak
Keyword(s):  
Numerical Solution ◽  
Natural Frequency ◽  
Contact Area ◽  
Nonlinear Oscillations ◽  
High Accuracy ◽  
Gap Size ◽  
Pressure Force ◽  
Optimum Range ◽  
The Given ◽  
Accuracy Degree

Carried out simulation of oscillations of a spring-loaded roll in a roll compactor when interacting the powder being compacted with the rolls. Considering the separation of the feed and compaction areas in the contact area of the roll with the material being compacted, we obtain the dependence of the force acting on the roll on the gap size between the rolls. It is shown that this dependence is non-linear, and it can be described with a sufficiently high accuracy degree by an exponential function with a negative exponent in the working range. The given numerical solution of the equation of free nonlinear oscillations of the spring-loaded roll has shown that considering the deformation of the material being compacted leads to a reduction of the natural frequency of the system by 20–25 % compared to the case, where the pressure force of the powder on the roll is assumed to be independent of the gap size. The nonlinearity of the dependence of the pressure force on the gap also leads to the increase by 10 % in the calculated values of the maximum displacements. The developed approach to the calculation of oscillations of the spring-loaded roll in the roll compactor enables to take into account the peculiarities of deformation of the powder being compacted during its interaction with the rolls. In addition, it allows estimating the frequencies and oscillation amplitudes and setting the optimum range of spring rate values, at which the occurrence of resonance in the machine is not possible.

Supersaturation of solutions in crystallisers with the well stirred suspension

1980 ◽  
Vol 45 (7) ◽  
pp. 1920-1927 ◽  
Author(s):  
Jaroslav Nývlt
Keyword(s):  
High Accuracy ◽  
Nucleation And Growth ◽  
Kinetic Constants ◽  
Derived Relations ◽  
Metastable Region ◽  
The Given

Relations were derived comparing the steady supersaturation in the continuous MSMPR and/or bath crystallisers with the stirred suspension having the maximum supersaturation corresponding to the boundary of metastable region at the given conditions. The derived relations include only the quantities used for the system constant BN from the corresponding crystallisation experiments. By use of supersaturation in the crystalliser obtained by the described method it is possible to evaluate the kinetic constants of nucleation and growth. However, it is not possible to expect a high accuracy of the data so obtained.

scholarly journals Automatic speech segmentation using throat-acoustic correlation coefficients

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Rustam Rafikovich Mussabayev ◽  
Maksat N. Kalimoldayev ◽  
Yedilkhan N. Amirgaliyev ◽  
Timur R. Mussabayev
Keyword(s):  
Large Volume ◽  
Automatic Segmentation ◽  
Correlation Coefficients ◽  
High Accuracy ◽  
Speech Segmentation ◽  
Preliminary Training ◽  
Effi Ciency ◽  
Segmentation Accuracy ◽  
New Type ◽  
The Given

Abstract This work considers one of the approaches to the solution of the task of discrete speech signal automatic segmentation. The aim of this work is to construct such an algorithm which should meet the following requirements: segmentation of a signal into acoustically homogeneous segments, high accuracy and segmentation speed, unambiguity and reproducibility of segmentation results, lack of necessity of preliminary training with the use of a special set consisting of manually segmented signals. Development of the algorithm which corresponds to the given requirements was conditioned by the necessity of formation of automatically segmented speech databases that have a large volume. One of the new approaches to the solution of this task is viewed in this article. For this purpose we use the new type of informative features named TAC-coefficients (Throat-Acoustic Correlation coefficients) which provide sufficient segmentation accuracy and effi- ciency.

scholarly journals Analytical and Experimental Analyses of Nonlinear Vibrations in a Rotary Inverted Pendulum

2021 ◽  
Author(s):  
Mohammadjavad Rahimi dolatabad ◽  
Abdolreza Pasharavesh ◽  
Amir Ali Akbar Khayyat
Keyword(s):  
Analytical Solution ◽  
Numerical Solution ◽  
Closed Loop ◽  
Inverted Pendulum ◽  
Multiple Scales ◽  
Nonlinear Oscillations ◽  
Wide Frequency Range ◽  
Perturbative Method ◽  
Full State Feedback ◽  
Rotary Inverted Pendulum

Abstract Gaining insight into possible vibratory responses of dynamical systems around their stable equilibria is an essential step, which must be taken before their design and application. The results of such a study can significantly help prevent instability in closed-loop stabilized systems through avoiding the excitation of the system in the neighborhood of its resonance. This paper investigates nonlinear oscillations of a Rotary Inverted Pendulum (RIP) with a full-state feedback controller. Lagrange’s equations are employed to derive an accurate 2-DoF mathematical model, whose parameter values are extracted by both the measurement and 3D modeling of the real system components. Although the governing equations of a 2-DoF nonlinear system are difficult to solve, performing an analytical solution is of great importance, mostly because, compared to the numerical solution, the analytical solution can function as an accurate pattern. Additionally, the analytical solution is generally more appealing to engineers because their computational costs are less than those of the numerical solution. In this study, the perturbative method of multiple scales is used to obtain an analytical solution to the coupled nonlinear motion equations of the closed-loop system. Moreover, the parameters of the controller are determined, using the results of this solution. The findings reveal the existence of hardening- and softening-type resonances at the first and second vibrational modes, respectively. This led to a wide frequency range with moderately large-amplitude vibrations, which must be avoided when adjusting a time-varying set-point for the system. The analytical results of the nonlinear vibration of the RIP are verified by experimental measurements, and a very good agreement is observed between the results of both approaches.

scholarly journals Single-Valued Neutrosophic Set Correlation Coefficient and Its Application in Fault Diagnosis

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1371
Author(s):  
Shchur Iryna ◽  
Yu Zhong ◽  
Wen Jiang ◽  
Xinyang Deng ◽  
Jie Geng
Keyword(s):  
Fault Diagnosis ◽  
Correlation Coefficient ◽  
Triangular Fuzzy Number ◽  
Neutrosophic Set ◽  
Mechanical Equipment ◽  
Inaccurate Information ◽  
The Given ◽  
Set Correlation ◽  
Accuracy Degree ◽  
Weighted Correlation

With the increasing automation of mechanical equipment, fault diagnosis becomes more and more important. However, the factors that cause mechanical failures are becoming more and more complex, and the uncertainty and coupling between the factors are getting higher and higher. In order to solve the given problem, this paper proposes a single-valued neutrosophic set ISVNS algorithm for processing of uncertain and inaccurate information in fault diagnosis, which generates neutrosophic set by triangular fuzzy number and introduces the formula of the improved weighted correlation coefficient. Since both the single-valued neutrosophic set data and the ideal neutrosophic set data are considered, the proposed method solves the fault diagnosis problem more effectively. Finally, experiments show that the algorithm can significantly improve the accuracy degree of fault diagnosis, and can better satisfy the diagnostic requirements in practice.

scholarly journals The relationship between the gross efficiency and the ability to repeat the given pressure force in trained cyclists

2019 ◽  
Vol 20 (1) ◽  
pp. 48-54
Author(s):  
Rafał Hebisz ◽  
Ryszard Błacha ◽  
Paulina Hebisz ◽  
Stefan Szczepan
Keyword(s):  
Pressure Force ◽  
Gross Efficiency ◽  
The Given ◽  
The Relationship

scholarly journals Reconstruction of Piecewise Smooth Multivariate Functions from Fourier Data

Axioms ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 88
Author(s):  
David Levin
Keyword(s):  
Fourier Series ◽  
Fourier Coefficients ◽  
Order Approximation ◽  
High Accuracy ◽  
Rectangular Domain ◽  
High Order ◽  
Piecewise Smooth ◽  
Multidimensional Case ◽  
Order Spline ◽  
The Given

In some applications, one is interested in reconstructing a function f from its Fourier series coefficients. The problem is that the Fourier series is slowly convergent if the function is non-periodic, or is non-smooth. In this paper, we suggest a method for deriving high order approximation to f using a Padé-like method. Namely, we do this by fitting some Fourier coefficients of the approximant to the given Fourier coefficients of f. Given the Fourier series coefficients of a function on a rectangular domain in Rd, assuming the function is piecewise smooth, we approximate the function by piecewise high order spline functions. First, the singularity structure of the function is identified. For example in the 2D case, we find high accuracy approximation to the curves separating between smooth segments of f. Secondly, simultaneously we find the approximations of all the different segments of f. We start by developing and demonstrating a high accuracy algorithm for the 1D case, and we use this algorithm to step up to the multidimensional case.

Singularity Consideration in Numerical Solution of Contact Stress Problems

1982 ◽  
Vol 104 (3) ◽  
pp. 352-356 ◽  
Author(s):  
L. Nayak
Keyword(s):  
Numerical Methods ◽  
Numerical Solution ◽  
Contact Stress ◽  
Contact Area ◽  
Fundamental Equation ◽  
Elliptic Functions ◽  
Contact Problems ◽  
Hertzian Contact ◽  
Elastic Displacement ◽  
Proper Analysis

The paper gives an account of different approaches to deal with the weak singularity in numerical methods of contact stress problems when the methods are based on the fundamental equation relating the elastic displacement with pressure. Singularity consideration in a new method to simultaneously determine the shape of the contact area and the pressure distribution, particularly in non-Hertzian contact problems, has been dealt with using elliptic functions. Necessity of proper analysis of singularity is discussed and the final results when compared with Hertz solution have been shown to be satisfactory.

scholarly journals Numerical Solution of Nonlinear Sine-Gordon Equation by Modified Cubic B-Spline Collocation Method

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
R. C. Mittal ◽  
Rachna Bhatia
Keyword(s):  
Numerical Solution ◽  
Collocation Method ◽  
Gordon Equation ◽  
Spline Collocation ◽  
Sine Gordon Equation ◽  
B Spline ◽  
Spline Collocation Method ◽  
B Splines ◽  
Spline Basis ◽  
The Given

Modified cubic B-spline collocation method is discussed for the numerical solution of one-dimensional nonlinear sine-Gordon equation. The method is based on collocation of modified cubic B-splines over finite elements, so we have continuity of the dependent variable and its first two derivatives throughout the solution range. The given equation is decomposed into a system of equations and modified cubic B-spline basis functions have been used for spatial variable and its derivatives, which gives results in amenable system of ordinary differential equations. The resulting system of equation has subsequently been solved by SSP-RK54 scheme. The efficacy of the proposed approach has been confirmed with numerical experiments, which shows that the results obtained are acceptable and are in good agreement with earlier studies.

The Study of Fulcrum Distance in the Pressure Straightening Process

2010 ◽  
Vol 145 ◽  
pp. 399-403
Author(s):  
Ya Qin Tian ◽  
Zhi Fei Wang ◽  
Qing Xue Huang ◽  
Jin Bao Li
Keyword(s):  
Contact Area ◽  
Minimum Distance ◽  
Pipe Wall ◽  
Pressure Head ◽  
Work Piece ◽  
Pressure Force ◽  
Pipe Wall Thickness ◽  
Optimal Distance ◽  
The Impact ◽  
The Relationship

In order to study the impact of fulcrum distance on the straightening the minimum fulcrum distance was determined based on the plastic theory according to straightening pressure force in the process of straightening process where there was no indentation. The optimal distance between the fulcrums straightening has been studied by using of bending curvature changes in the bending deflection formula and support the relationship between the dot pitch. Given initial deflection according to bending deflection and bending deflection the amount range of the fulcrum distance can be determined during the pressure straightening. When the rate of bending deflection determined it can obtain the fulcrum distance at the same curvature. The more fulcrums distance the more bending deflection. The minimum fulcrum distance was three times the power growth with the diameter of work piece. The minimum fulcrum distance is inverse proportion to contact area of pressure head. With the pipe wall thickness decreases the minimum distance also reduced.

Sign in / Sign up

Export Citation Format

Share Document