Paper 13: The Dynamics of Valve Mechanisms

Author(s):  
D. E. G. Crutcher

The paper deals with a computer program that has been developed to study the dynamic behaviour of poppet valve mechanisms. A theoretical analysis is performed on a single mass, single degree of freedom system subjected to internal and external viscous damping and Coulomb friction, representing a valve mechanism with flexible overhead linkage. Measurements have been made on engines so that computed and experimental results could be compared in order to test the program. The effect on performance of varying the dynamic parameters of valve mechanisms is investigated with the computer program.

1971 ◽  
Vol 93 (1) ◽  
pp. 67-73 ◽  
Author(s):  
M. S. C. Yuan ◽  
F. Freudenstein ◽  
L. S. Woo

The basic concepts of screw coordinates described in Part I are applied to the numerical kinematic analysis of spatial mechanisms. The techniques are illustrated with reference to the displacement, velocity, and static-force-and-torque analysis of a general, single-degree-of-freedom spatial mechanism: a seven-link mechanism with screw pairs (H)7. By specialization the associated computer program is capable of analyzing many other single-loop spatial mechanisms. Numerical examples illustrate the results.


Author(s):  
Silvio Sorrentino ◽  
Luigi Garibaldi

This paper presents a study of the frequency domain behaviour of a single degree of freedom (SDOF) system with a fractional derivative model, named Fractional Kelvin-Voigt. Frequency response functions (FRFs) as receptance and transmissibility are analytically studied. Then the model is applied to describe the dynamic behaviour of a magneto-mechanic system in the frequency domain, consisting of a body of para or dia-magnetic material vibrating in a field created by a pair of magnets.


Robotica ◽  
2006 ◽  
Vol 25 (3) ◽  
pp. 307-313
Author(s):  
Brian J. Driessen ◽  
Nader Sadegh

SUMMARYIn this paper, we consider the problem of rest-to-rest maneu-ver learning, via iterative learning control (ILC), for single-degree-of-freedom systems with stick-slip Coulomb friction and input bounds. The static coefficient of friction is allowed to be as large as three times the kinetic coefficient of friction. The input is restricted to be a two-pulse one. The desired input's first pulse magnitude is required to be five times the largest possible kinetic (sliding) friction force. The theory therefore allows the stiction force to be as large as the desired second input pulse. Under these conditions, we prove global convergence of a simple iterative learning controller. To the best of our knowledge, such a global-convergence proof has not been presented previously in the literature for the rest-to-rest problem with stick-slip Coulomb friction.


1960 ◽  
Vol 82 (4) ◽  
pp. 369-375
Author(s):  
Will J. Worley

The behavior of a single degree of freedom system consisting of a single mass mounted on a spring and damper attached to an oscillating base is investigated. Steady-state and transient sinusoidal oscillations are applied to the base to which the suspension is attached. The response of the mass is recorded for various combinations of linear and nonlinear springs and dampers. Solutions are obtained with a differential analyzer.


2018 ◽  
Vol 147 ◽  
pp. 05003
Author(s):  
Heri Setiawan ◽  
Muslim Muin

When a ship is moving through another ship moored nearby, hydrodynamic interactions between these ships result in movements of the moored vessel. The movement may occur as surge, sway, and/or yaw. When a ship is passing a moored vessel parallelly, this effect will give a dominant lateral force on the moored ship and response from this phenomenon will appear in a certain time. Only dynamic response due to sway force is considered in this study, the sway force shall be absorb by the breasting dolphin. 40,000 DWT shall be moored to the breasting dolphin. Three passing ships size are considered, the breasting dolphin shall be modeled as a single degree of freedom model. This model will be subjected to a force caused by parallel passing ship. The model is assumed to be in a state of quiet water, this assumption is taken so that the fluid does not provide additional force on the model. The SDOF system shall be analyzed using a computer program designed to solve an ordinary differential equation.


1984 ◽  
Vol 106 (4) ◽  
pp. 280-285 ◽  
Author(s):  
Etsuo Marui ◽  
Shinobu Kato

Using the “stopping region of motion” concept, a brief analytical technique is worked out for the behavior of the linear forced vibratory system under the influence of a Coulomb friction force. The following points are clarified by the above technique: 1. The behavior of the system is completely determined by the three non-dimensional parameters of nondimensional friction force, frequency ratio and damping ratio. 2. The vibratory system undergoes a periodic vibration with stopping periods when the mass cannot move. These stopping periods increase at lower exciting frequencies, owing to Coulomb friction. 3. The relation between the kind of motion occurring in the system and the above three parameters can be obtained theoretically and verified experimentally.


1969 ◽  
Vol 11 (6) ◽  
pp. 592-597 ◽  
Author(s):  
W. Carnegie ◽  
Z. F. Reif

The ultraharmonic resonance of order 2, excited by a centrifugal type disturbing force, is investigated for a single-degree-of-freedom system with a Duffing restoring force characteristic. The effect of gravity is taken into account. The resulting asymmetry of the restoring force is expressed in terms of the static deflection parameter. The Ritz averaging method is used for the theoretical analysis and the results are verified by means of an analogue computer.


1969 ◽  
Vol 36 (4) ◽  
pp. 871-873 ◽  
Author(s):  
E. V. Wilms

The equation of motion of a single-degree-of-freedom mechanical system with Coulomb friction acting at two bearings is derived. The equation is nonlinear, but may be solved by piecewise linearization. For the case of transient oscillations, the amplitude decreases by a constant ratio every half cycle and, in this respect, the behavior resembles that of viscous damping rather than the type of Coulomb damping which has previously been investigated. The steady-state response with a forcing function is determined for the case of small damping. In addition to the amplitude and phase angle of the motion, a solution requires the determination of a second angle which defines the linearized regions.


2004 ◽  
Vol 11 (3-4) ◽  
pp. 209-225 ◽  
Author(s):  
Elvio Bonisoli ◽  
John E. Mottershead

The fact that a complex-damped model may represent the dynamic behaviour of elasto-mechanical systems when acted upon by a magnetic field was brought to the attention of the structural dynamics community very recently by Professor Bruno A. D. Piombo and his colleagues at the Politecnico di Torino. In this paper a thorough analysis of the single degree-of-freedom complex-damped mass-spring system is presented. The analysis includes the root locus, the (non-causal) impulse response, the frequency response and the transmissibility. Regions of different behaviour in the frequency response and transmissibility are described in detail. The stiffening behaviour observed in Prof. Piombo's experiments and known as the "phantom effect" is demonstrated by the complex-damped model.


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