A Hertz contact model with non-linear damping for pounding simulation

2006 ◽  
Vol 35 (7) ◽  
pp. 811-828 ◽  
Author(s):  
Susendar Muthukumar ◽  
Reginald DesRoches
Keyword(s):  
Contact Model ◽  
Hertz Contact ◽  
Non Linear ◽  
Linear Damping ◽  
Hertz Contact Model

Modified Analytical Expression of Damping Constant in the Hertz Contact Model with Non-Linear Damping for Structural Pounding

2010 ◽  
Vol 29-32 ◽  
pp. 220-225 ◽  
Author(s):  
Kun Ye ◽  
Rong Fu ◽  
Sha Qi Ma
Keyword(s):  
Impact Force ◽  
Analytical Formula ◽  
Nonlinear Damping ◽  
Coefficient Of Restitution ◽  
Contact Model ◽  
Spring Stiffness ◽  
Hertz Contact ◽  
Structural Pounding ◽  
Linear Damping ◽  
Hertz Contact Model

Structural pounding under earthquakes has been recently extensively investigated by using different models of impact force. In this paper, reexamination into the Hertz contact model with nonlinear damping is made. Based upon this reexamination, the formula used to determine the damping constant in terms of the spring stiffness, the coefficient of restitution and relative approaching velocity of two colliding bodies is found to be wrong. In order to correct this error, a more accurate approximating formula for the damping constant is theoretically derived. The correctness of the derived analytical formula has been confirmed through numerical simulations.

Dynamic Interaction of Vehicle and Discontinuous Slab Track Considering Nonlinear Hertz Contact Model

2016 ◽  
Vol 142 (4) ◽  
pp. 04016011 ◽  
Author(s):  
Javad Sadeghi ◽  
Amin Khajehdezfuly ◽  
Morteza Esmaeili ◽  
Davood Poorveis
Keyword(s):  
Dynamic Interaction ◽  
Contact Model ◽  
Hertz Contact ◽  
Slab Track ◽  
Hertz Contact Model

scholarly journals A cell-based mechanical model of coronary artery tunica media

2017 ◽  
Vol 14 (132) ◽  
pp. 20170028 ◽  
Author(s):  
N. B. Melnikova ◽  
A. I. Svitenkov ◽  
D. R. Hose ◽  
A. G. Hoekstra
Keyword(s):  
Coronary Artery ◽  
Mechanical Model ◽  
Adhesive Contact ◽  
Contact Model ◽  
Chain Model ◽  
Hertz Contact ◽  
Wormlike Chain ◽  
Tunica Media ◽  
Hertz Contact Model

A three-dimensional cell-based mechanical model of coronary artery tunica media is proposed. The model is composed of spherical cells forming a hexagonal close-packed lattice. Tissue anisotropy is taken into account by varying interaction forces with the direction of intercellular connection. Several cell-centre interaction potentials for repulsion and attraction are considered, including the Hertz contact model and its neo-Hookean extension, the Johnson–Kendall–Roberts model of adhesive contact, and a wormlike chain model. The model is validated against data from in vitro uni-axial tension tests performed on dissected strips of tunica media. The wormlike chain potential in combination with the neo-Hookean Hertz contact model produces stress–stretch curves which represent the experimental data very well.

ANALYSIS OF HIGH-SPEED RAIL ACCOUNTING FOR JUMPING WHEEL PHENOMENON

2014 ◽  
Vol 11 (03) ◽  
pp. 1343007 ◽  
Author(s):  
KOK KENG ANG ◽  
JIAN DAI ◽  
MINH THI TRAN ◽  
VAN HAI LUONG
Keyword(s):  
High Speed ◽  
Computational Study ◽  
Dynamic Responses ◽  
Contact Model ◽  
High Speed Train ◽  
Train Track ◽  
Hertz Contact ◽  
High Speed Rail ◽  
Track System ◽  
Hertz Contact Model

In this paper, a computational study using the moving element method (MEM) was carried out to investigate the dynamic response of a high-speed train–track system. Results obtained using Hertz contact model and linearized Hertz contact model are compared and discussed. The dynamic responses of a train travelling across a uniform foundation and a transition region are also investigated. Parametric study is performed to understand the effect of various factors on the occurrence and patterns of the jumping wheel phenomenon such as the variation of foundation stiffness, travelling speed of the train and the severity of railhead roughness.

scholarly journals Axisymmetric Contact Problem for a Flattened Cell: Contributions of Substrate Effect and Cell Thickness to the Determination of Viscoelastic Properties by Using AFM Indentation

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Xinyao Zhu ◽  
Lanjiao Liu ◽  
Zuobin Wang ◽  
X. Liu
Keyword(s):  
Mechanical Properties ◽  
Linear Elasticity ◽  
Viscoelastic Properties ◽  
Present Model ◽  
Finite Thickness ◽  
Contact Model ◽  
Substrate Effect ◽  
Biological Cells ◽  
Hertz Contact ◽  
Hertz Contact Model

Nanoindentation technology has proven to be an effective method to investigate the viscoelastic properties of biological cells. The experimental data obtained by nanoindentation are frequently interpreted by Hertz contact model. However, in order to validate Hertz contact model, some studies assume that cells have infinite thickness which does not necessarily represent the real situation. In this study, a rigorous contact model based upon linear elasticity is developed for the interpretation of indentation tests of flattened cells. The cell, normally bonded to the Petri dish, is initially treated as an elastic layer of finite thickness perfectly fixed to a rigid substrate. The theory of linear elasticity is utilized to solve this contact issue and then the solutions are extended to viscoelastic situation which is regarded as a good indicator for mechanical properties of biological cells. To test the present model, AFM-based creep test has been conducted on living human hepatocellular carcinoma cell (SMMC-7721 cell) and its fullerenol-treated counterpart. The results indicate that the present model could not only describe very well the creep behavior of SMMC-7721 cells, but also curb overestimation of the mechanical properties due to substrate effect.

Parameter design methodologies for vertical skewed line gears taking lubrication performance into account

2019 ◽  
Vol 233 (10) ◽  
pp. 1496-1507
Author(s):  
Yangzhi Chen ◽  
Anshi Zhu ◽  
Yueling Lyu
Keyword(s):  
Simulation Experiment ◽  
Design Method ◽  
Elastohydrodynamic Lubrication ◽  
Contact Model ◽  
Parameter Design ◽  
Design Parameters ◽  
Hertz Contact ◽  
Design Methodologies ◽  
Lubrication Performance ◽  
Hertz Contact Model

Based on the elastohydrodynamic lubrication (EHL) theory, design methodologies are proposed aiming to improve the EHL state of the vertical skewed line gear (VSLG) in this article. First of all, the parametric equations of the driving and driven VSLG surfaces are established and then converted into equivalent Hertz contact model. Then, the influences of the design parameters of the VSLG on the ellipticity are analyzed by its equivalent Hertz contact model. Finally, the parameter design method for improving the EHL state of VSLG is deduced. The results of optical elastohydrodynamic experiment and simulation experiment indicate that the parameter design method is effective for the formation of EHL film without changing the kinematic characteristics of VSLG. In short, this paper provides reliable and convenient parameter design methods for VSLG in consideration of EHL.

scholarly journals Non-linear damping for scattering-passive systems in the Maxwell class

2020 ◽  
Vol 53 (2) ◽  
pp. 7458-7465
Author(s):  
Shantanu Singh ◽  
George Weiss ◽  
Marius Tucsnak
Keyword(s):  
Passive Systems ◽  
Non Linear ◽  
Linear Damping

Energy Balancing Method to Identify Nonlinear Damping of Bolted-Joint Interface

2016 ◽  
Vol 693 ◽  
pp. 318-323 ◽  
Author(s):  
Xin Liao ◽  
Jian Run Zhang
Keyword(s):  
Dry Friction ◽  
Harmonic Excitation ◽  
Joint Interface ◽  
Damping Factor ◽  
Viscous Damping ◽  
Bolted Joint ◽  
Energy Balancing ◽  
Stick Slip ◽  
Non Linear ◽  
Linear Damping

The interface of bolted joint commonly focuses on the research of non-linear damping and stiffness, which affect structural response. In the article, the non-linear damping model of bolted-joint interface is built, consisting of viscous damping and Coulomb friction. Energy balancing method is developed to identify the dry-friction parameter and viscous damping factor. The corresponding estimation equations are acquired when the input is harmonic excitation. Then, the vibration experiments with different bolted preloads are conducted, from which amplitudes in various input levels are used to work out the interface parameters. Also, the fitting curves of dry-friction parameters are also obtained. Finally, the results illustrate that the most interface of bolted joint in lower excitation levels occurs stick-slip motion, and the feasibility of the identification approach is demonstrated.

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