Normal Vibrations and Friction at a Hertzian Contact Under Random Excitation: Perturbation Solution

1993 ◽  
Vol 164 (2) ◽  
pp. 317-326 ◽  
Author(s):  
D.P. Hess ◽  
A. Soom
Keyword(s):  
Random Excitation ◽  
Perturbation Solution ◽  
Hertzian Contact ◽  
Normal Vibrations

Normal Vibrations and Friction Under Harmonic Loads: Part I—Hertzian Contacts

1991 ◽  
Vol 113 (1) ◽  
pp. 80-86 ◽  
Author(s):  
D. P. Hess ◽  
A. Soom
Keyword(s):  
Nonlinear Vibrations ◽  
Multiple Scales ◽  
Normal Load ◽  
Perturbation Technique ◽  
Friction Reduction ◽  
Hertzian Contact ◽  
Dynamic Component ◽  
Normal Contact ◽  
Normal Vibrations ◽  
Contact Parameters

Nonlinear vibrations at a Hertzian contact are studied by the perturbation technique known as the method of multiple scales. The vibrations are excited by the dynamic component of an externally applied normal load. Solutions are obtained for both the average and instantaneous contact deflections. As a result of the nonlinear Hertzian stiffness, the average normal contact deflection during oscillations is smaller than the static deflection under the same average load. It is shown that this can result in a reduction of the average area of contact and, by implication, the average friction force in the presence of even small dynamic loads. The parametric dependence of the normal motion on the various contact parameters is investigated. It is shown that the maximum average friction reduction without contact loss is approximately ten percent.

Seismic Pounding Model Using Hertzian Contact

2018 ◽  
Author(s):  
Arthur Mereles ◽  
Marcus Varanis ◽  
José Manoel Balthazar ◽  
Angelo Marcelo Tusset
Keyword(s):  
Hertzian Contact ◽  
Seismic Pounding

scholarly journals Improved design criterion for frictionally engaged contacts in overrunning clutches

2021 ◽  
Author(s):  
Nadine Nagler ◽  
Armin Lohrengel
Keyword(s):  
Design Process ◽  
Contact Area ◽  
Axial Load ◽  
State Of The Art ◽  
Tangential Force ◽  
Design Criterion ◽  
Hertzian Contact ◽  
Loss Of Function ◽  
Axial Loads ◽  
Improved Design

AbstractOverrunning clutches, also known as freewheel clutches, are frictionally engaged, directional clutches; they transmit torque depending on the Freewheel clutch rings’ rotation directions. The torque causes a tangential force in the Hertzian contact area. The hitherto “state-of-the-art design criterion” bases on this load situation. In practice, axial loads additionally act on the frictionally engaged Hertzian contact area. This additional axial load can cause the loss of the friction connection and so the freewheel clutch slips. This publication presents an improved design criterion for frictionally engaged contacts in freewheel clutches. It allows to consider tangential as well as axial loads during the design process. Additionally, it offers the possibility to estimate the probability of frictional engagement loss and gross slip based on the freewheel clutch’s application scenario. This publication points out how to use the improved design criterion to design freewheel clutches that are more robust against a loss of function.

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