Numerical Simulations of Slider Interaction With Multiple Asperity Using Hertzian Contact Model

1995 ◽  
Vol 117 (4) ◽  
pp. 575-579 ◽  
Author(s):  
Ellis Cha ◽  
D. B. Bogy
Keyword(s):  
Disk Drive ◽  
Contact Model ◽  
Hertzian Contact ◽  
Flying Height ◽  
Radius Of Curvature ◽  
Asperity Contact ◽  
Disk Contact ◽  
Suspension Dynamics ◽  
Magnetic Hard Disk ◽  
Hertzian Contact Model

A numerical simulation of slider-disk contact in a magnetic hard disk drive is studied using the Hertzian contact model. The slider-disk contact is caused by flying height fluctuation due to disk runout for very low flying sliders. The rough disk topography is generated numerically by combining a sinusoidal waviness and a Gaussian roughness. For each asperity contact, the radius of curvature is calculated from the disk topography, and the radius is used to calculate the contact force using the Hertzian contact model. The slider’s response to a single asperity calculated using the Hertzian contact model agrees well with the result obtained using the impulse-momentum based contact model. The simulation results of slider-disk contact including suspension dynamics are calculated with and without friction for a “nano-slider.”

Small correction required when applying the Hertzian contact model to instrumented indentation data

2001 ◽  
Vol 16 (5) ◽  
pp. 1280-1286 ◽  
Author(s):  
J. L. Hay ◽  
P. J. Wolff
Keyword(s):  
Mechanical Properties ◽  
Contact Model ◽  
Hertzian Contact ◽  
Test Material ◽  
Contact Radius ◽  
Test Surface ◽  
Instrumented Indentation ◽  
Hardness Testing ◽  
Small Correction ◽  
Hertzian Contact Model

Instrumented indentation testing (IIT) is a relatively new form of mechanical testing which significantly expands on the capabilities of traditional hardness testing. In an IIT experiment, an indenter of known mechanical properties is pressed into contact and then withdrawn from a test material. The fundamental measurements during an IIT experiment are the applied load and the resulting penetration of the indenter into the test surface. The Hertzian contact model, or a derivative thereof, is often employed to relate these measurements to interesting mechanical properties of the test material. This article argues for a small correction to the Hertzian contact model when applied to instrumented indentation data. The magnitude of the correction primarily depends on Poisson's ratio of the test material and the contact radius normalized by the radius of the indenter tip. Neglecting this correction can cause significant errors in the calculation of elastic modulus and hardness from instrumented indentation data.

A vibration model of a rotor system with the sinusoidal waviness by using the non-Hertzian solution

2021 ◽  
pp. 146441932110659
Author(s):  
Jing Liu ◽  
Chenyu An ◽  
Guang Pan
Keyword(s):  
Accurate Method ◽  
Rotor System ◽  
Contact Forces ◽  
Contact Model ◽  
Hertzian Contact ◽  
Rigid Rotor ◽  
Nonlinear Contact ◽  
Reasonable Approach ◽  
Almost All ◽  
Hertzian Contact Model

The nonlinear contact forces and deformations between the balls and raceways can cause very complex vibration behaviours of rotor systems with the waviness in the support bearings. However, almost all previous works that used sinusoidal waviness took the Hertzian solution as the calculation method, which is not an accurate method based on Johnson’s formulation since the changes in the curvature at the sinusoidal contact surfaces. To overcome this issue, a new dynamic model of a rigid rotor system with the waviness in the support bearings is proposed. To provide a more accurate nonlinear contact force formulation for the sinusoidal waviness profile, the model used the Johnson’s extended Hertzian contact model to replace Hertzian contact model. This model can consider the time-varying curvature between the mating sinusoidal surfaces. The lubricating condition in the support bearing is also considered. A comparative study on the effects of Hertzian contact model, simplified Hertzian contact model, and Johnson's extended Hertzian contact model on the nonlinear vibrations of the rotor system is developed. The effects of the waviness amplitude and orders on the vibrations of the rotor system are discussed. The comparative simulations show that the proposed model can provide a more reasonable approach for predicting the vibrations of the rigid rotor system. Moreover, the simulations give that the nonlinear contact forces in the support bearings can greatly affect the system vibrations.

A multi-Hertzian contact model considering plasticity

Wear ◽  
2014 ◽  
Vol 314 (1-2) ◽  
pp. 118-124 ◽  
Author(s):  
Michel Sebès ◽  
Hugues Chollet ◽  
Jean-Bernard Ayasse ◽  
Luc Chevalier
Keyword(s):  
Contact Model ◽  
Hertzian Contact ◽  
Hertzian Contact Model

scholarly journals Stochastic Responses for the Vibro-Impact System under the Broadband Noise

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
S. W. Guan ◽  
Q. Ling ◽  
M. Xu
Keyword(s):  
Classical Model ◽  
Side Wall ◽  
Stochastic Averaging ◽  
Broadband Noise ◽  
Contact Model ◽  
Hertzian Contact ◽  
Impact System ◽  
Random Responses ◽  
The Impact ◽  
Hertzian Contact Model

The stochastic averaging is applied to derive the random responses of the SDOF vibro-impact system with one-side wall under additive and multiplicative broadband noise, where the impact is described by the modified Hertzian contact model. Compared with the popular simplified “classical model” (i.e., x˙−=rx˙+), the whole impact process is captured by the modified Hertzian contact model without any assumptions. One example is given to illustrate the proposed technique. The comparison between the analytical results and those from Monte Carlo simulations manifests the accuracy of the proposed technique. It should be pointed out that the technique proposed in this paper is powerful for the cases of weak excitation and big enough bandwidth of the broadband noise. Finally, the influences of various parameters are also discussed in detail.

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