scholarly journals A Physically Consistent Model for Forced Torsional Vibrations of Automotive Driveshafts

Computation ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 10
Author(s):  
Mihai Bugaru ◽  
Andrei Vasile
Keyword(s):  
Dynamic Behavior ◽  
Torsional Rigidity ◽  
Twist Angle ◽  
Moment Of Inertia ◽  
Torsional Vibrations ◽  
Consistent Model ◽  
Axial Moment ◽  
Torsional Damping ◽  
Torsional Loads ◽  
Inner Race

The aim of this research was to design a physically consistent model for the forced torsional vibrations of automotive driveshafts that considered aspects of the following phenomena: excitation due to the transmission of the combustion engine through the gearbox, excitation due to the road geometry, the quasi-isometry of the automotive driveshaft, the effect of nonuniformity of the inertial moment with respect to the longitudinal axis of the tulip–tripod joint and of the bowl–balls–inner race joint, the torsional rigidity, and the torsional damping of each joint. To resolve the equations of motion describing the forced torsional nonlinear parametric vibrations of automotive driveshafts, a variational approach that involves Hamilton’s principle was used, which considers the isometric nonuniformity, where it is known that the joints of automotive driveshafts are quasi-isometric in terms of the twist angle, even if, in general, they are considered CVJs (constant velocity joints). This effect realizes the link between the terms for the torsional vibrations between the elements of the driveshaft: tripode–tulip, midshaft, and bowl–balls–inner race joint elements. The induced torsional loads (as gearbox torsional moments that enter the driveshaft through the tulip axis) can be of harmonic type, while the reactive torsional loads (as reactive torsional moments that enter the driveshaft through the bowl axis) are impulsive. These effects induce the resulting nonlinear dynamic behavior. Also considered was the effect of nonuniformity on the axial moment of inertia of the tripod–tulip element as well as on the axial moment of inertia of the bowl–balls–inner race joint element, that vary with the twist angle of each element. This effect induces parametric dynamic behavior. Moreover, the torsional rigidity was taken into consideration, as was the torsional damping for each joint of the driveshaft: tripod–joint and bowl–balls–inner race joint. This approach was used to obtain a system of equations of nonlinear partial derivatives that describes the torsional vibrations of the driveshaft as nonlinear parametric dynamic behavior. This model was used to compute variation in the natural frequencies of torsion in the global tulip (a given imposed geometry) using the angle between the tulip–midshaft for an automotive driveshaft designed for heavy-duty SUVs as well as the characteristic amplitude frequency in the region of principal parametric resonance together the method of harmonic balance for the steady-state forced torsional nonlinear vibration of the driveshaft. This model of dynamic behavior for the driveshaft can be used during the early stages of design as well in predicting the durability of automotive driveshafts. In addition, it is important that this model be added in the design algorithm for predicting the comfort elements of the automotive environment to adequately account for this kind of dynamic behavior that induces excitations in the car structure.

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.

The Dynamic Behavior of a Rolling Element Auxiliary Bearing Following Rotor Impact

2001 ◽  
Vol 124 (2) ◽  
pp. 406-413 ◽  
Author(s):  
M. O. T. Cole ◽  
P. S. Keogh ◽  
C. R. Burrows
Keyword(s):  
Dynamic Behavior ◽  
Angular Acceleration ◽  
Element Model ◽  
Magnetic Bearing ◽  
Rolling Element Bearing ◽  
Linear Matrix ◽  
Rolling Element ◽  
Non Linear ◽  
In Series ◽  
Inner Race

The dynamic behavior of a rolling element bearing under auxiliary operation in rotor/magnetic bearing systems is analyzed. When contact with the rotor occurs, the inner race experiences high impact forces and rapid angular acceleration. A finite element model is used to account for flexibility of the inner race in series with non-linear ball stiffnesses arising from the ball-race contact zones. The dynamic conditions during rotor/inner race contact, including ball/race creep, are deduced from a non-linear matrix equation. The influences of bearing parameters are considered together with implications for energy dissipation in the bearing.

DRIVE COUPLING WITH SPLIT STEEL SLEEVES

2020 ◽  
pp. 32-34
Author(s):  
V. M. Zyablikov ◽  
B. V. Buketkin ◽  
V. F. Smirnov ◽  
A. A. Shirshov
Keyword(s):  
Torsional Rigidity ◽  
Gear Wheel ◽  
Dynamic Loads ◽  
Torsional Vibrations ◽  
Small Curvature ◽  
Elastic Elements

The main purpose of couplings with elastic elements is to reduce dynamic loads and reduce the level of dangerous vibration amplitudes. Sometimes it is necessary for this purpose to install such couplings directly in the units, since they have large amplitudes of torsional vibrations. Drive couplings with elastic elements – steel split sleevescan be installed inside the units. The design of the coupling, which is built into the gear wheel of the reducer, is shown. The main characteristic of drive clutches with elastic elements is torsional rigidity. A detailed output of the formula for calculating the stiffness of such couplings is given. The conclusion is based on determining the deformation of split sleeves taken as rods of small curvature.

scholarly journals The properties of torsional vibrations in reciprocating engine shafts. —Part II

1926 ◽  
Vol 113 (764) ◽  
pp. 272-281 ◽  
Keyword(s):  
Moment Of Inertia ◽  
Experimental Results ◽  
Effective Length ◽  
Torsional Vibrations ◽  
Static Tests ◽  
Reciprocating Engine ◽  
The Mean ◽  
The Moment

In order to compare with the experimental results, the algebraic values of the results just obtained will be converted into numbers, using the dimensions adopted in the experiment. The shaft used was a steel rod ⅜-inch in diameter. From the contact of fly-wheel A to that of fly-wheel E was 78¾ inches, and from fly-wheel A to the crank (see fig. 1) was 81¼ inches. The mean of these, or 80 inches, was takenas the effective length. The modulus of rigidity, taken from static tests, was found to be 11.4 x 10 6 lbs. per square inch. The moment of inertia of fly-wheel A was about 15,000 lbs. (inches) 2 . The fly-wheel E was tested experimentally, and its moment of inertia found to be 194·2 lbs. (inches) 2 . The crank radius, a , was 2 inches.

scholarly journals Determination of tangential properties of a single pneumatic tire in the vehicle braking mode of a vehicle

2021 ◽  
pp. 28-34
Author(s):  
Valeriy Klimenko ◽  
Denis Kapski ◽  
Dmytro Leontiev ◽  
Oleksandr Kuripka ◽  
Andrii Frolov
Keyword(s):  
Coefficient Of Friction ◽  
Simulation Modeling ◽  
Torsional Rigidity ◽  
Dynamic Change ◽  
Twist Angle ◽  
Road Surface ◽  
Pneumatic Tire ◽  
The Road ◽  
On The Road ◽  
Pneumatic Tires

Problem. In the event of circumstances that may cause a traffic accident (accident), drivers apply emergency braking, which usually leads to the blocking of car wheels and the formation on the road surface of track information from pneumatic tires. If automated brake force control systems are installed in the brake actuator of the vehicle, the tracking information from the pneumatic tires may be absent or weak, and the braking efficiency of the wheeled vehicle will depend on the angular deformation of the tire relative to the road surface, which in turn is limited. coupling properties in the contact spot "tire-road surface". Goal. The aim of the work is to improve the method of determining the angle of twist of the pneumatic tire of a single car wheel in the mode of its braking by taking into account the effects of the coefficient of friction-sliding on roads with high traction. Methodology the peculiarities of twisting the pneumatic tire of a car wheel with a single busbar in the mode of vehicle braking on roads with low and high coefficient of friction - sliding are considered. The analysis of the model of dynamic change of the tire twist angle depending on the sliding of the tire tread elements in the spot of contact with the road surface is performed, and the results of simulation modeling are obtained, which are confirmed by experimental experiments. Originality. An empirical dependence is proposed, which takes into account the nature of the decrease in the value of the angle of twist of the tire on roads with high traction properties. Practical value. The obtained results of simulation modeling according to the proposed dependence determine that the highest indicators of torsional rigidity of the pneumatic tire are reached at a tire pressure of 0.8 MPa and a vertical load on it of about 2.6 104 N.

INFLUENCE OF RIGIDITY OF ELASTIC ELEMENTS OF COUPLING COUPLINGS ON TORSIONAL VIBRATION OF SHUNTING LOCOMOTIVES DRIVES

2021 ◽  
pp. 30-35
Author(s):  
A. P. Evdokimov
Keyword(s):  
Torsional Vibration ◽  
Continued Fractions ◽  
Torsional Rigidity ◽  
Torsional Vibrations ◽  
Elastic Coupling ◽  
Elastic Elements

The results of calculations of torsional vibrations of elements of power drives of shunting locomotives with different torsional rigidity of rubbercord shells of elastic coupling couplings are presented. Based on the results obtained, the choice of rubbercord shells is justified depending on their torsional rigidity. The basis for the choice of shells is the obtained results of calculations of the resonant amplitudes of torsional vibrations by the method of continued fractions.

scholarly journals Rule-based equation for elastic tripping analysis of angle bar stiffeners

2012 ◽  
Vol 9 (2) ◽  
pp. 103-111 ◽  
Author(s):  
Ahmad Rahbar Ranji
Keyword(s):  
Energy Method ◽  
Flexural Rigidity ◽  
Torsional Rigidity ◽  
Beam Theory ◽  
Moment Of Inertia ◽  
Rule Base ◽  
Rule Based ◽  
Buckling Modes ◽  
Polar Moment ◽  
Marine Engineering

Tripping is one of buckling modes in stiffened plates which could be occurred in the stiffeners with high flexural rigidity and low torsional rigidity. Rule-base expressions for calculation of sectorial moment of inertia of angle-bar stiffeners are scattered. An expression for calculation of sectorial moment of inertia of angle-bar stiffeners is derived based on energy method and beam theory. Sectorial moment of inertia of different angle-bar stiffeners are calculated and compared with the values calculated by different classification society rules. It is found that some of the rule-based equations for calculation of sectorial moment of inertia of angle-bar stiffeners are inaccurate. Euler tripping stress of different angle bars are calculated by energy method and compared with rule-based equation and finite element method. It is found that, rule-based expression for calculation of polar moment of inertia of angle-bar stiffeners neglects one term, which could lead up to 10% overestimation of Euler tripping stress. DOI: http://dx.doi.org/10.3329/jname.v9i2.10443 Journal of Naval Architecture and Marine Engineering 9(2012) 105-111

Texture and Mechanical Behavior of Magnesium During Free-End Torsion

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Benoît Beausir ◽  
László S. Tóth ◽  
Fathallah Qods ◽  
Kenneth W. Neale
Keyword(s):  
Room Temperature ◽  
Texture Evolution ◽  
Twist Angle ◽  
Rolled Plate ◽  
Electron Backscattering Diffraction ◽  
Consistent Model ◽  
End Conditions ◽  
Different Temperatures ◽  
Initial Texture ◽  
Hexagonal Crystals

Torsion experiments were carried out on pure magnesium (99.9%) and the magnesium alloy AZ71 under free-end conditions of testing. The alloy had an axisymmetric initial texture, while the pure Mg samples were prepared from a rolled plate with a nonaxisymmetric initial texture. The torque as a function of the twist angle was measured at different temperatures (room temperature, 150°C, and 250°C). During twisting, systematic shortening of the samples was observed (Swift effect). The evolution of the crystallographic texture was analyzed by electron backscattering diffraction measurements. The occurrence of dynamic recrystallization (DRX) was detected in pure Mg at 250°C. The Swift effect in the axisymmetric samples was simulated with the “equilibrium equation” approach using polycrystal modeling. In the nonaxisymmetric samples, the texture was simulated at different angular positions with the help of the viscoplastic self-consistent model. The changes in the textures due to DRX were explained in terms of the Taylor factor. Finally, the texture evolution was interpreted with the help of the behavior of ideal orientations and persistence characteristics of hexagonal crystals in simple shear.

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