scholarly journals Diversity and Regularity of Periodic Impact Motions of a Mechanical Vibration System with Multiple Rigid Stops

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Fengwei Yin ◽  
Guanwei Luo ◽  
Xueming Wang
Keyword(s):  
Dynamic Characteristics ◽  
Simulation Analysis ◽  
Equations Of Motion ◽  
Mechanical Vibration ◽  
Low Frequency ◽  
Model Parameters ◽  
Vibration System ◽  
Parametric Plane ◽  
Parameter Matching ◽  
Dynamical Parameters

The mechanical model of a two-degree-of-freedom vibration system with multiple rigid stops was established, and the effects of the multiple rigid stops to dynamic characteristics of two mass blocks of the system were studied. The judgment conditions and differential equations of motion of the system masses impacting rigid stops were analyzed. Based on the multiparameter and multiobjective collaborative simulation analysis, the correlation between the dynamic characteristics of the vibration system and the model parameters is studied. The basic periodic and subharmonic impact motions are analyzed with emphasis on the influences of dynamical parameters on the mode diversity and the distribution characteristics, and the law of emergence and competition of various periodic impact motions on the parametric plane is revealed. The singular points, the hysteresis transition domains, and the accompanying codimension-two bifurcations, caused by the irreversibility of the transition between adjacent basic periodic impact motions in the low-frequency domain, are analyzed. The reasonable parameter matching range, associated with dynamic characteristic optimization of the system, is determined.

On establishing equations of motion of mechanical vibration systems placed on moving bases

2017 ◽  
Vol 45 (3) ◽  
pp. 209-227
Author(s):  
M Gürgöze ◽  
F Terzioğlu
Keyword(s):  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Mechanical Vibration ◽  
Main Idea ◽  
Vertical Axis ◽  
Constant Angular Velocity ◽  
Vibration System ◽  
Reaction Forces ◽  
The Subject ◽  
Vibrating Systems

The first author has been teaching the postgraduate course, “The Dynamics of Mechanical Systems” in The ITU Faculty of Mechanical Engineering for nearly 20 years. He has observed that students frequently have problems in obtaining the equations of motion of the vibrating systems which were placed on moving bases. Starting from this observation, he has found that the homework stated below, which was given to the students occasionally, was very helpful in learning the subject. The main idea of the homework is the derivation of the equations of motion, with the help of formulating the Lagrange’s equations with respect to a moving set of axis for a vibration system with two degrees of freedom which consists of a horizontal table rotating with a constant angular velocity around a vertical axis. The students were also asked to solve the same problem with a different method of their choice and to determine the reaction forces as well. We want to share this problem with the reader, which we have assessed as very instructive and appropriate from the viewpoint of applicability of different methods.

The Research on the Spindle Vibration State Suppressor after Remanufacturing

2014 ◽  
Vol 644-650 ◽  
pp. 4677-4681
Author(s):  
Ling Liu
Keyword(s):  
Simulation Analysis ◽  
Active Vibration Control ◽  
Mechanical Vibration ◽  
Image Data ◽  
Order System ◽  
Vibration System ◽  
Linear Quadratic ◽  
Linear Quadratic Optimal Control ◽  
Inherent Frequency ◽  
Spindle Vibration

The overhung spindle system is studied as the object after remanufacturing, the spindle simplified cantilever and the mathematical model was established based on the simplified equivalent device. The simulation analysis of the dual cantilever was carried out by using ANSYS.The vibration mode and inherent frequency of the cantilever, the deformation caused by the applied loads was given in this paper.It is designed by the linear quadratic optimal control of two state regulator through analyzing the vibration form and loading condition,use of independent modal control algorithm based on the detection of the position feedback control,It is inhibited effectively when a cantilever beam subjected to external transient pulse disturbance caused by two order and higher order system mode vibration,and using the Matlab software programming for active vibration control effects simulation.In addition.Matlab software gave the image result of response of vibration system.Both the brief solution program and the accurate image data which corresponded with vibration theory showed the feasibility and superiority during solving these responses of the spindle vibration system after remanufacturing.Thereby,this research provided an easy and effective method to solve the response of general mechanical vibration system.

The Mechanical Model of the Dynamic Characteristics of the Bituminous Concrete Compaction Mechanism

2013 ◽  
Vol 483 ◽  
pp. 266-270
Author(s):  
Lin Long Zhu
Keyword(s):  
Dynamic Characteristics ◽  
Mechanical Model ◽  
Design Theory ◽  
Engineering Application ◽  
Vibration System ◽  
Theoretical Significance ◽  
Vibration Compaction ◽  
Dynamical Parameters ◽  
Working Performance ◽  
Bituminous Concrete

In view of the industry status that the working performance of domestic bituminous concrete paver is not ideal and corresponding design theory is lack, this paper proposes the compaction system structures of screeding devices, sets up differential equations of vibration system of the freedom degree of the double eccentric block vibration compaction mechanism, sets up the mechanical model of dynamic characteristics of ironing compaction mechanism. With computer simulation, it studies the problems of dynamics of ironing compaction mechanism, analyzes the influence of changes of dynamical parameters of the ironing compaction mechanism on the dynamic characteristics of the system. The study of the dynamic response of ironing compaction systems and dynamic design has important theoretical significance and engineering application value.

Model of vortex flow of charge in a vessel with turbine impeller

1987 ◽  
Vol 52 (8) ◽  
pp. 1888-1904
Author(s):  
Miloslav Hošťálek ◽  
Ivan Fořt
Keyword(s):  
Boundary Conditions ◽  
Equations Of Motion ◽  
Theoretical Data ◽  
Eddy Diffusion ◽  
Quantitative Agreement ◽  
Creeping Flow ◽  
Model Parameters ◽  
Mean Flow ◽  
Two Dimensional Flow ◽  
Vorticity Transport

A theoretical model is described of the mean two-dimensional flow of homogeneous charge in a flat-bottomed cylindrical tank with radial baffles and six-blade turbine disc impeller. The model starts from the concept of vorticity transport in the bulk of vortex liquid flow through the mechanism of eddy diffusion characterized by a constant value of turbulent (eddy) viscosity. The result of solution of the equation which is analogous to the Stokes simplification of equations of motion for creeping flow is the description of field of the stream function and of the axial and radial velocity components of mean flow in the whole charge. The results of modelling are compared with the experimental and theoretical data published by different authors, a good qualitative and quantitative agreement being stated. Advantage of the model proposed is a very simple schematization of the system volume necessary to introduce the boundary conditions (only the parts above the impeller plane of symmetry and below it are distinguished), the explicit character of the model with respect to the model parameters (model lucidity, low demands on the capacity of computer), and, in the end, the possibility to modify the given model by changing boundary conditions even for another agitating set-up with radially-axial character of flow.

scholarly journals Motor shifting and torque distribution control of a multi-motor driving system in electric construction vehicles

2021 ◽  
Vol 13 (6) ◽  
pp. 168781402110284
Author(s):  
Weikang Kong ◽  
Jixin Wang ◽  
Dewen Kong ◽  
Yuanying Cong ◽  
Shuangshi Feng
Keyword(s):  
Power Systems ◽  
Control Method ◽  
Simulation Analysis ◽  
Rapid Development ◽  
Transmission Efficiency ◽  
Torque Distribution ◽  
Driving System ◽  
Construction Machinery ◽  
Improve Energy Efficiency ◽  
Parameter Matching

With the rapid development of the world economic construction and the shortage of energy, it has become a hot research issue to realize the electrification of the vehicle driving system and improve energy efficiency. Most of the electric construction machinery power systems are characterized by low speed and high load. The coordinated driving of multiple motors can increase the output torque and improve the transmission efficiency of the machine on the basis of a compact layout. A novel configuration of electric construction vehicles based on multi-motor and single-speed and its driving torque distribution control method is presented in this paper. The detailed mathematical model is established and the simulation analysis is carried out based on it. The results show that the proposed multi-motor driving system with the control strategy can improve the overall efficiency in the condition of ensuring the driving force when the parameter matching and motors choosing reasonably.

Analytical Solution for Rotational Rub-Impact Plate Under Thermal Shock

2016 ◽  
Vol 32 (3) ◽  
pp. 297-311
Author(s):  
T.-Y. Zhao ◽  
H.-Q. Yuan ◽  
B.-B. Li ◽  
Z.-J. Li ◽  
L.-M. Liu
Keyword(s):  
Thermal Shock ◽  
High Frequency ◽  
Equations Of Motion ◽  
Low Frequency ◽  
Cantilever Plate ◽  
Analysis Method ◽  
Multiple Frequency ◽  
Width Direction ◽  
Blade Tip ◽  
High Frequency Vibrations

AbstractThe analysis method is developed to obtain dynamic characteristics of the rotating cantilever plate with thermal shock and tip-rub. Based on the variational principle, equations of motion are derived considering the differences between rubbing forces in the width direction of the plate. The transverse deformation is decomposed into quasi-static deformation of the cantilever plate with thermal shock and dynamic deformation of the rubbing plate under thermal shock. Then deformations are obtained through the calculation of modal characteristics of rotating cantilever plate and temperature distribution function. Special attention is paid to the influence of tip-rub and thermal shock on the plate. The results show that tip-rub has the characteristics of multiple frequency vibrations, and high frequency vibrations are significant. On the contrary, thermal shock shows the low frequency vibrations. The thermal shock makes the rubbing plate gradually change into low frequency vibrations. Because rub-induced vibrations are more complicated than those caused by thermal shock, tip-rub is easier to result in the destruction of the blade. The increasing friction coefficient intensifies vibrations of the rubbing plate. Minimizing friction coefficients can be an effective way to reduce rub-induced damage through reducing the surface roughness between the blade tip and the inner surface of the casing.

Simulation of Engine Vibration on Nonlinear Hydraulic Engine Mounts

2005 ◽  
Author(s):  
A. R. Ohadi ◽  
G. Maghsoodi
Keyword(s):  
Equations Of Motion ◽  
Low Frequency ◽  
Governing Equations ◽  
Engine Mounts ◽  
Engine Vibration ◽  
Engine Mount ◽  
Rotational Motions ◽  
The Time Domain ◽  
Nonlinear Equations Of Motion ◽  
Four Cylinders

In this paper, vibration behavior of engine on nonlinear hydraulic engine mount including inertia track and decoupler is studied. In this regard, after introducing the nonlinear factors of this mount (i.e. inertia and decoupler resistances in turbulent region), the vibration governing equations of engine on one hydraulic engine mount are solved and the effect of nonlinearity is investigated. In order to have a comparison between rubber and hydraulic engine mounts, a 6 degree of freedom four cylinders V-shaped engine under inertia and balancing masses forces and torques is considered. By solving the time domain nonlinear equations of motion of engine on three inclined mounts, translational and rotational motions of engines body are obtained for different engine speeds. Transmitted base forces are also determined for both types of engine mount. Comparison of rubber and hydraulic mounts indicates the efficiency of hydraulic one in low frequency region.

Modeling the Climber Fall Arrest Dynamics

2005 ◽  
Author(s):  
Lionel Manin ◽  
Jarir Mahfoudh ◽  
Matthieu Richard ◽  
David Jauffres
Keyword(s):  
Dynamic Characteristics ◽  
Equations Of Motion ◽  
Close Approximation ◽  
Non Linear ◽  
The Future ◽  
Safety Recommendations ◽  
Improved Design ◽  
Fall Arrest

Sports and mountaineering activities are becoming more and more popular. Equipment constructors seek to develop products and devices that are easy to use and that take into account all safety recommendations. PETZL and INSA have collaborated to develop a model for the simulation of displacements and efforts involved during the fall of a climber in the “safety chain”. The model is based on the classical equations of motion, in which climber and belayer are considered as rigid masses, while the rope is considered as a series of non-linear stiffness passing through several devices as brakes and runners. The main goal is to predict the forces in the rope and on the return anchor at the first rebound of the fall. Experiments were first performed in order to observe and determine the dynamic characteristics of the rope, and then to validate results stemming from simulations. Several fall configurations are simulated, and the model performs satisfactorily. It also provides a close approximation of the phenomena observed experimentally. The model enables the assessment of the existing equipments and the improved design of the future one.

Multirate Integration for Multibody Dynamic Analysis With Decomposed Subsystems

1999 ◽  
Author(s):  
Sung-Soo Kim ◽  
Jeffrey S. Freeman
Keyword(s):  
Dynamic Analysis ◽  
Multibody System ◽  
Equations Of Motion ◽  
Low Frequency ◽  
Inertia Force ◽  
Integration Scheme ◽  
Integration Algorithm ◽  
Multibody Dynamic ◽  
Higher Order Derivative ◽  
Derivative Information

Abstract This paper details a constant stepsize, multirate integration scheme which has been proposed for multibody dynamic analysis. An Adams-Bashforth Moulton integration algorithm has been implemented, using the Nordsieck form to store internal integrator information, for multirate integration. A multibody system has been decomposed into several subsystems, treating inertia coupling effects of subsystem equations of motion as the inertia forces. To each subsystem, different rate Nordsieck form of Adams integrator has been applied to solve subsystem equations of motion. Higher order derivative information from the integrator provides approximation of inertia force computation in the decomposed subsystem equations of motion. To show the effectiveness of the scheme, simulations of a vehicle multibody system that consists of high frequency suspension motion and low frequency chassis motion have been carried out with different tire excitation forces. Efficiency of the proposed scheme has been also investigated.

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