scholarly journals Determination of inertia-stiffness parameters and motion modelling of three-mass vibratory system with crank excitation mechanism

2021 ◽  
Vol 36 ◽  
pp. 7-12
Author(s):  
Vitaliy Korendiy ◽  
Oleksii Lanets ◽  
Oleksandr Kachur ◽  
Petro Dmyterko ◽  
Roman Kachmar
Keyword(s):  
Excitation Mechanism ◽  
Vibratory System

scholarly journals Direct Method for the Determination of Coefficients of Characteristic Equation of a MDOF System

2019 ◽  
Vol 15 (2) ◽  
pp. 26-31
Author(s):  
Mahesh Chandra Luintel
Keyword(s):  
Characteristic Equation ◽  
Natural Frequencies ◽  
Direct Method ◽  
Degree Of Freedom ◽  
Mode Shapes ◽  
Vibratory System ◽  
Single Degree Of Freedom ◽  
Dynamic Matrix ◽  
Eigen Values

Dynamic response of any single degree of freedom (SDOF) vibratory system is studied by evaluating its natural frequencies whereas that of any multi degree of freedom (MDOF) vibratory system is studied by evaluating its natural frequencies and corresponding mode shapes. Efficient method to determine the natural frequencies and mode shape of a MDOF system is to determine its dynamic matrix and to calculate its eigen-values and eigen-vectors. As the number of degree of freedom (DOF) of the system increases, the size of the dynamic matrix increases and the use of a computer program or package become essential. Hence this paper proposes a new method to directly calculate the coefficients of characteristic equation of any degree of freedom system from which eigen-values and then natural frequencies can be determined.  

scholarly journals An Evaluation of the Fixed Point Method of Vibration Analysis for a Particular System With Initial Damping

1963 ◽  
Vol 85 (3) ◽  
pp. 233-236 ◽  
Author(s):  
D. B. Bogy ◽  
P. R. Paslay
Keyword(s):  
Steady State ◽  
Approximate Method ◽  
Fixed Point Method ◽  
Steady State Response ◽  
Vibratory System ◽  
State Response ◽  
System Use ◽  
Two Degree Of Freedom ◽  
Maximum Steady State

The maximum steady-state response of a particular linear damped two-degree-of-freedom vibratory system is minimized by determining the optimum damping constant for a single damper. This is accomplished by both a well-known approximate method and by an exact numerical method. Since the approximate method does not take into account the damping which is initially in the system, attention in this analysis is directed to determining the influence of the initial damping on the optimum value for the single damper. In order to make direct comparison of the methods, a system was chosen in which an exact numerical determination of the optimum damping was possible. The results of the investigation show for the particular case considered that, although the value of the damping constant for the optimum damper increases considerably as initial damping is included in the system, use of the value obtained for the initially undamped case would give values of the maximum steady-state response within 10 percent of the optimized value for the range of initial damping commonly encountered.

Determination of System Damping From the Response Amplitude at Resonance

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Peter J. Torvik
Keyword(s):  
Response Amplitude ◽  
Hard Coatings ◽  
Resonant Peak ◽  
Mode Shapes ◽  
Quality Factors ◽  
Vibratory System ◽  
Element Analysis ◽  
At Resonance ◽  
The Ideal

A method for estimating the damping of a vibratory system from the frequency of resonance and the response amplitude at that resonant peak alone is reviewed and applied to the determination of the system loss or quality factors of uniform, rectangular cantilever bare titanium beams and beams with damping enhancing hard coatings. Using results from experiments with several different nonlinear coating systems vibrating in several modes and temperatures, comparisons are given for the damping measures obtained by this method with those obtained by the traditional method for determining system damping from the bandwidth (BW) of the frequency response functions (FRFs). These comparisons, made for strains of engineering interest (to strains over 1000 ppm), show that the BW method generally leads to inflated measures of system energy dissipation and that the inflation (10–70%) depends generally on the degree of nonlinearity, i.e., the extent to which the system loss factor varies with strain amplitude. While developed for the ideal uniform, rectangular, cantilever beam for which the mode shapes are well known, the method may be applied to more complex geometries through the use of a finite element analysis (FEA).

scholarly journals Determination of the first natural frequency of an elastic rod of a discrete-continuous vibratory system

2021 ◽  
Vol 37 ◽  
pp. 7-12
Author(s):  
Vitaliy Korendiy ◽  
Oleksii Lanets ◽  
Oleksandr Kachur ◽  
Petro Dmyterko ◽  
Sergij Nikipchuk ◽  
...  
Keyword(s):  
Natural Frequency ◽  
Elastic Rod ◽  
Vibratory System

Determination of the Natural Frequencies of a Nearly Uniform System

1972 ◽  
Vol 39 (4) ◽  
pp. 918-922 ◽  
Author(s):  
H. Bergkvist
Keyword(s):  
Natural Frequency ◽  
Natural Frequencies ◽  
Slide Rule ◽  
Vibratory System ◽  
Numerical Examples ◽  
Uniform System ◽  
Important Type ◽  
System A

The equation giving the natural frequencies ωi of vibrations in a nearly uniform system is obtained from the knowledge of the natural frequencies of a uniform system and elementary determinant expansion. By inspection of the equation a sequence of frequency intervals is immediately found, each one containing one natural frequency. This fact makes the method superior to the classical Holzer method for this important type of vibratory system. A closer determination of the ωi:s, that sometimes could be needed, is easily performed by use of a simple desk-top calculator or even a slide rule, as is illustrated by some numerical examples in the Appendix.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Sign in / Sign up

Export Citation Format

Share Document