scholarly journals Experimental Study on Torsional Vibration of Transmission System Under Engine Excitation

2017 ◽  
Author(s):  
Xin YANG ◽  
Tie-shan ZHANG ◽  
Nan-lin LEI
Keyword(s):  
Experimental Study ◽  
Torsional Vibration ◽  
Transmission System ◽  
Engine Excitation

Experimental Study on Torsional Vibration of Dual Mass Flywheel

2012 ◽  
Vol 490-495 ◽  
pp. 2318-2322
Author(s):  
De Min Chen ◽  
Jin Hao Xu ◽  
Xiao Fei Shi ◽  
Yue Yin Ma
Keyword(s):  
Experimental Study ◽  
Torsional Vibration ◽  
Power Transmission ◽  
Transmission System ◽  
Test Bed ◽  
Testing Apparatus ◽  
Damping Effect ◽  
Damping Effects ◽  
Transmission Test

To verify the damping effect of dual mass flywheel, the experiment is designed in use of power-transmission test-bed and rev-torque testing apparatus, and dual mass flywheel of DCT transmission system DQ250 is used to test its damping effect in the experiment. Kinds of conditions of car, like idle condition, run condition, climb condition, are simulated in experiment. The results show that different engine revs and loads, different damping effects of dual mass flywheel. The high engine rev and the more load, the better damping effect of dual mass flywheel.

Experimental Study on Lateral and Torsional Vibration of Cracked Rotor With Torsional Excitation

2013 ◽  
Author(s):  
Chao Liu ◽  
Dongxiang Jiang
Keyword(s):  
Experimental Study ◽  
Normal Condition ◽  
Torsional Vibration ◽  
Transverse Crack ◽  
Rotating Machinery ◽  
Lateral Vibration ◽  
Cracked Rotor ◽  
Diagnostic Features ◽  
Slant Crack ◽  
Torsional Excitation

Crack failures in rotating machinery can result in catastrophic accidents, and they are are difficult to detect online. Condition monitoring is widely applied in field to detect changes of vibration, and form diagnostic features. However, effective features in vibration of the cracked rotor need more tests, especially validating the features with experiments. This work carried out an experimental study on cracked rotors in laboratory. The experiments are as following: (I) vibration of the rotor in normal condition is firstly tested, where lateral vibration and torsional vibration are measured; (II) torsional excitation is exerted on driven end of rotor system, and vibration characteristics of the rotor are tested; (III) cracked rotors are tested with transverse and slant cracks, respectively. With the measured signals, comparisons of vibrations in normal rotor and cracked rotors are carried out. The results show that, the transverse crack introduces more significant changes in 1X frequency and coupled frequency, while the slant crack employs larger changes in 2X frequency. And variation of phases of 1X frequency is presented. Also, the crack plays an impact on the torsional responses.

scholarly journals Experimental Study of the Shaft Penetration Factor on the Torsional Dynamic Response of a Drive Train

Machines ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 31 ◽  
Author(s):  
Hans Meeus ◽  
Björn Verrelst ◽  
David Moens ◽  
Patrick Guillaume ◽  
Dirk Lefeber
Keyword(s):  
Experimental Study ◽  
Torsional Vibration ◽  
Torsional Stiffness ◽  
Vibration Measurement ◽  
Dynamic Amplification Factor ◽  
Torsional Mode ◽  
Penetration Factor ◽  
Torsional Response ◽  
Major Interest ◽  
Drive Trains

Typical rotating machinery drive trains are prone to torsional vibrations. Especially those drive trains that comprise one or more couplings which connect the multiple shafts. Since these vibrations rarely produce noise or vibration of the stationary frame, their presence is hardly noticeable. Moreover, unless an expensive torsional-related problem has become obvious, such drive trains are not instrumented with torsional vibration measurement equipment. Excessive levels can easily cause damage or even complete failure of the machine. So, when designing or retrofitting a machine, a comprehensive and detailed numerical torsional vibration analysis is crucial to avoid such problems. However, to accurately calculate the torsional modes, one has to account for the penetration effect of the shaft in the coupling hub, indicated by the shaft penetration factor, on the torsional stiffness calculation. Many guidelines and assumptions have been published for the stiffness calculation, however, its effect on the damping and the dynamic amplification factor are less known. In this paper, the effect of the shaft penetration factor, and hence coupling hub-to-shaft connection, on the dynamic torsional response of the system is determined by an experimental study. More specifically, the damping is of major interest. Accordingly, a novel academic test setup is developed in which several configurations, with each a different shaft penetration factor, are considered. Besides, different amplitude levels, along with both a sweep up and down excitation, are used to identify their effect on the torsional response. The measurement results show a significant influence of the shaft penetration factor on the system’s first torsional mode. By increasing the shaft penetration factor, and thus decreasing the hub-to-shaft interference, a clear eigenfrequency drop along with an equally noticeable damping increase, is witnessed. On the contrary, the influence of the sweep up versus down excitation is less pronounced.

Identification of firefly algorithm-based fluctuation coefficient of the exciting torque for vehicle driveline

2018 ◽  
Vol 233 (2) ◽  
pp. 317-326
Author(s):  
Qiaobin Liu ◽  
Wenku Shi ◽  
Zhiyong Chen
Keyword(s):  
Torsional Vibration ◽  
Firefly Algorithm ◽  
Vibration Response ◽  
Theoretical Modelling ◽  
Lumped Mass ◽  
Mass Model ◽  
Engine Torque ◽  
Lumped Mass Model ◽  
Vibration Performance ◽  
Engine Excitation

The unbalanced excitation force and torque generated by an engine that resonate with the natural frequency of drivetrain often causes vibration and noise problems in vehicles. This study aims to comprehensively employ theoretical modelling and experimental identification methods to obtain the fluctuation coefficients of engine excitation torque when a car is in different gear positions. The inherent characteristics of the system are studied on the basis of the four-degree-of-freedom driveline lumped mass model and the longitudinal dynamics model of vehicle. The correctness of the model is verified by torsional vibration test. The second order's engine torque fluctuation coefficients are identified by firefly algorithm according to the curves of flywheel speed in different gears under the acceleration condition of the whole open throttle. The torque obtained by parameter identification is applied to the model, and the torsional vibration response of the system is analysed. The influence of the key parameters on the torsional vibration response of the system is investigated. The study concludes that proper reduction of clutch stiffness can increase clutch damping and half-axle rigidity, which can help improve the torsional vibration performance of the system. This study can provide reference for vehicle drivetrain modelling and torsional vibration control.

A new torsional vibration coupling model for transmission system in diesel generator

2021 ◽  
pp. 146808742110689
Author(s):  
Bin Chen ◽  
Yunbo Hu ◽  
Yibin Guo ◽  
Zhijun Shuai ◽  
Chongpei Liu ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Torsional Vibration ◽  
Coupling Model ◽  
Transmission System ◽  
System Matrix ◽  
Diesel Generator ◽  
Lumped Mass ◽  
Proposed Model ◽  
Torsional Coupling ◽  
Vibration Coupling

The coupling between the crankshaft and the camshaft is neglected before in fault diagnosis which may lead to incomplete fault information. In this paper, a new torsional coupling model of a diesel generator transmission system is proposed for fault diagnosis. The natural frequency and forced torsional vibration response of the model are obtained by the system matrix method and Newmark-β method. For the system without considering the lumped mass of camshafts, some key natural frequencies are lost. The vibration dynamics are compared for the transmission system with and without the new coupling model. And important frequency responses are missed in the spectrums of the forced torsional vibration without the new coupling model. Finally, the new coupling model is implemented in fault diagnosis and the cause of an unusual vibration fault is deduced in the simulation, which confirms the feasibility of the proposed model in fault diagnosis.

An Experimental Study of Torsional Vibration Absorbers

2001 ◽  
Author(s):  
Alan G. Haddow ◽  
Steven W. Shaw
Keyword(s):  
Experimental Study ◽  
Dynamic Behavior ◽  
Systematic Study ◽  
Torsional Vibration ◽  
Theoretical Background ◽  
Controlled Environment ◽  
Vibration Absorbers ◽  
Test Apparatus ◽  
First Time ◽  
Theoretical Results

Abstract This paper presents results from tests completed on a rotor system fitted with pendulum-type torsional vibration absorbers. A review of the associated theoretical background is also given and the experimental and theoretical results are compared and contrasted. An overview of the test apparatus is provided and its unique features are discussed. To the best knowledge of the authors, this is the first time that a systematic study of the dynamic behavior of torsional vibration absorbers has been undertaken in a controlled environment.

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