scholarly journals Fundamental study on countermeasures against subharmonic vibration of order 1/2 in automatic transmissions for cars

2018 ◽  
Vol 211 ◽  
pp. 13004
Author(s):  
Fumiya Takino ◽  
Takahiro Ryu ◽  
Takashi Nakae ◽  
Kenichiro Matsuzaki ◽  
Risa Ueno
Keyword(s):  
Piecewise Linear ◽  
Vibration Reduction ◽  
System Model ◽  
Torsional Vibrations ◽  
Fundamental Study ◽  
Automatic Transmissions ◽  
Linear Spring ◽  
Low Stiffness ◽  
Subharmonic Vibration ◽  
The One

In automatic transmissions for cars, a damper is installed in the lock-up clutch to absorb torsional vibrations caused by combustion in the engine. Although a damper with low stiffness reduces the torsional vibration, low-stiffness springs are difficult to use because of space limitations. To address this problem, dampers have been designed using a piecewise-linear spring having three different stages of stiffness. However, a nonlinear subharmonic vibration of order 1/2 occurs because of the nonlinearity of the piecewise-linear spring in the damper. In this study, we experimentally and analytically examined a countermeasure against the subharmonic vibration by increasing the stages of the piecewise-linear spring using the one-degree-of-freedom system model. We found that the gap between the switching points of the piecewise-linear spring was the key to vibration reduction. The experimental results agreed with results of the numerical analyses.

Effect of Stiffness Ratio of Piecewise-Linear Spring on the Occurrence of Subharmonic Nonlinear Vibration in Automatic Transmission Powertrain

2015 ◽  
Vol 786 ◽  
pp. 156-160 ◽  
Author(s):  
Takahiro Ryu ◽  
S. Rosbi ◽  
K. Matsuzaki ◽  
T. Nakae ◽  
A. Sueoka ◽  
...  
Keyword(s):  
Nonlinear System ◽  
Nonlinear Vibration ◽  
Forced Vibration ◽  
Piecewise Linear ◽  
Automatic Transmission ◽  
Torque Converter ◽  
Degree Of Freedom ◽  
Stiffness Ratio ◽  
Linear Spring ◽  
Subharmonic Vibration

In the torque converter, a damper with a piecewise-linear spring is used to reduce the forced vibration, and the subharmonic vibration occurs when the spring restoring torque characteristics approach the switching point. This research analyzed the effect of stiffness ratio between the neighboring piecewise-linear springs on the occurrence of the subharmonic nonlinear vibration in automatic transmission powertrain. The powertrain is modeled with multi degree-of-freedom nonlinear system as an actual vehicle. The result shows higher value of the stiffness ratio between the neighboring springs creates larger value of the subharmonic vibration.

scholarly journals Fundamental study of subharmonic vibration of order 1/2 in automatic transmissions for cars

2016 ◽  
Vol 744 ◽  
pp. 012206
Author(s):  
T Ryu ◽  
T Nakae ◽  
K Matsuzaki ◽  
A Nanba ◽  
Y Takikawa ◽  
...  
Keyword(s):  
Fundamental Study ◽  
Automatic Transmissions ◽  
Subharmonic Vibration

scholarly journals Topological guided-mode resonances at non-Hermitian nanophotonic interfaces

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ki Young Lee ◽  
Kwang Wook Yoo ◽  
Youngsun Choi ◽  
Gunpyo Kim ◽  
Sangmo Cheon ◽  
...  
Keyword(s):  
Fundamental Study ◽  
One Dimensional ◽  
Guided Mode ◽  
Wall Structures ◽  
Potential Applications ◽  
Photonic Microstructures ◽  
Guided Mode Resonance ◽  
The One ◽  
Photonic Band ◽  
Topological Correlations

Abstract The topological properties of photonic microstructures are of great interest because of their experimental feasibility for fundamental study and potential applications. Here, we show that robust guided-mode-resonance states exist in photonic domain-wall structures whenever the complex photonic band structures involve certain topological correlations in general. Using the non-Hermitian photonic analogy of the one-dimensional Dirac equation, we derive essential conditions for photonic Jackiw-Rebbi-state resonances taking advantage of unique spatial confinement and spot-like spectral features which are remarkably robust against random parametric errors. Therefore, the proposed resonance configuration potentially provides a powerful method to create compact and stable photonic resonators for various applications in practice.

A Method of Reinforcement and Vibration Reduction of Girder Bridges Using Shape Memory Alloy Cables

2017 ◽  
Vol 17 (07) ◽  
pp. 1750076 ◽  
Author(s):  
Ai-Rong Liu ◽  
Chun-Hui Liu ◽  
Ji-Yang Fu ◽  
Yong-Lin Pi ◽  
Yong-Hui Huang ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Traffic Safety ◽  
Torsional Rigidity ◽  
Vibration Reduction ◽  
Torsional Vibrations ◽  
Moving Vehicle ◽  
Girder Bridges ◽  
Fe Simulations ◽  
Vehicle Loads

Bending and torsional vibrations caused by moving vehicle loads are likely to affect the traffic safety and comfort for girder bridges with limited torsional rigidity. This paper studies the use of cables made of shape memory alloy (SMA) as the devices of reinforcement and vibration reduction for girder bridges. The SMA cables are featured by their small volume, expedient installation. To investigate their effect on the vibration of girder bridges, theoretical analysis, numerical simulation and experimental study were conducted in this paper. For bending vibration, the governing equations of the girder with and without SMA cables subjected to moving vehicle loads were derived, while for torsional vibration, the finite element (FE) simulations were used instead. The results of bending and torsional vibrations obtained by the analytical approach and FE simulations, respectively, were compared with the experimental ones from model testing. It was confirmed that the SMA cables can restrain the vibration of the girder bridge effectively.

Nonlinear Dynamics of One-Way Clutches in Belt-Pulley Systems

2003 ◽  
Author(s):  
Farong Zhu ◽  
Robert G. Parker
Keyword(s):  
Nonlinear Dynamics ◽  
Degrees Of Freedom ◽  
Piecewise Linear ◽  
Primary Resonance ◽  
Harmonic Balance Method ◽  
Excitation Amplitude ◽  
Relative Displacement ◽  
Second Primary ◽  
Arc Length ◽  
The One

One-way clutches are frequently used in the serpentine belt accessory drives of automobiles and heavy vehicles. The clutch plays a role similar to a vibration absorber in order to reduce belt/pulley vibration and noise and increase belt life. This paper analyzes a two-pulley system where the driven pulley has a one-way clutch between the pulley and accessory shaft that engages only for positive relative displacement between these components. The belt is modeled with linear springs that transmit torque from the driving pulley to the accessory pulley. The one-way clutch is modeled as a piecewise linear spring with discontinuous stiffness that separates the driven pulley into two degrees of freedom (DOF). The harmonic balance method (HBM) combined with arc-length continuation is employed to illustrate the nonlinear dynamic behavior of the one-way clutch. HBM with arc-length continuation yields the stable and unstable periodic solutions for given parameters. These solutions are examined across a range of excitation frequencies. The results are confirmed by numerical integration and the widely used bifurcation software AUTO. At the first primary resonance, most of the responses are aperiodic, including quasiperiodic and chaotic solutions. At the second primary resonance, the peak bends to the left with classical softening nonlinearity because clutch disengagement decouples the pulley and the accessory over portions of the response period. The dependence on system parameters such as clutch stiffness, excitation amplitude, and inertia ratio between the pulley and accessory is studied to characterize the nonlinear dynamics across a range of conditions.

Sons of the Earth: Are the Stoics Metaphysical Brutes?

Phronesis ◽  
2009 ◽  
Vol 54 (2) ◽  
pp. 136-154 ◽  
Author(s):  
Katja Maria Vogt
Keyword(s):  
Fundamental Study ◽  
The Earth ◽  
Crucial Component ◽  
The One ◽  
The Universe ◽  
The Way

AbstractIn this paper, it is argued the Stoics develop an account of corporeals that allows their theory of bodies to be, at the same time, a theory of causation, agency, and reason. The paper aims to shed new light on the Stoics' engagement with Plato's Sophist. It is argued that the Stoics are Sons of the Earth insofar as, for them, the study of corporeals – rather than the study of being – is the most fundamental study of reality. However, they are sophisticated Sons of the Earth by developing a complex notion of corporeals. A crucial component of this account is that ordinary bodies are individuated by the way in which the corporeal god pervades them. The corporeal god is the one cause of all movements and actions in the universe.

scholarly journals Analysis of Asymmetric Piecewise Linear Stochastic Resonance Signal Processing Model Based on Genetic Algorithm

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Lina He ◽  
Chuan Jiang
Keyword(s):  
Genetic Algorithm ◽  
Fault Detection ◽  
Stochastic Resonance ◽  
Signal To Noise Ratio ◽  
Piecewise Linear ◽  
Poor Performance ◽  
System Model ◽  
Adaptive Genetic Algorithm ◽  
Resonance System ◽  
Noise Energy

The stochastic resonance system has the advantage of making the noise energy transfer to the signal energy. Because the existing stochastic resonance system model has the problem of poor performance, an asymmetric piecewise linear stochastic resonance system model is proposed, and the parameters of the model are optimized by a genetic algorithm. The signal-to-noise ratio formula of the model is derived and analyzed, and the theoretical basis for better performance of the model is given. The influence of the asymmetric coefficient on system performance is studied, which provides guidance for the selection of initial optimization range when a genetic algorithm is used. At the same time, the formula is verified and analyzed by numerical simulation, and the correctness of the formula is proved. Finally, the model is applied to bearing fault detection, and an adaptive genetic algorithm is used to optimize the parameters of the system. The results show that the model has an excellent detection effect, which proves that the model has great potential in fault detection.

scholarly journals Gravity-driven thin liquid films with insoluble surfactant: smooth traveling waves

2007 ◽  
Vol 18 (6) ◽  
pp. 679-708 ◽  
Author(s):  
RACHEL LEVY ◽  
MICHAEL SHEARER ◽  
THOMAS P. WITELSKI
Keyword(s):  
Free Surface ◽  
Traveling Waves ◽  
Surfactant Concentration ◽  
Piecewise Linear ◽  
Traveling Wave Solutions ◽  
Liquid Films ◽  
Insoluble Surfactant ◽  
Small Parameters ◽  
Gravity Driven ◽  
The One

The flow of a thin layer of fluid down an inclined plane is modified by the presence of insoluble surfactant. For any finite surfactant mass, traveling waves are constructed for a system of lubrication equations describing the evolution of the free-surface fluid height and the surfactant concentration. The one-parameter family of solutions is investigated using perturbation theory with three small parameters: the coefficient of surface tension, the surfactant diffusivity, and the coefficient of the gravity-driven diffusive spreading of the fluid. When all three parameters are zero, the nonlinear PDE system is hyperbolic/degenerate-parabolic, and admits traveling wave solutions in which the free-surface height is piecewise constant, and the surfactant concentration is piecewise linear and continuous. The jumps and corners in the traveling waves are regularized when the small parameters are nonzero; their structure is revealed through a combination of analysis and numerical simulation.

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