scholarly journals Strength of the shaft/hub joint using a finite element model

2019 ◽  
pp. 9-18
Author(s):  
Manuel Salgado-Cruz ◽  
Claudia Cortés-García ◽  
Dariusz Slawomir Szwedowicz-Wasik ◽  
Eladio Martínez-Rayón
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Contact Stiffness ◽  
Load Capacity ◽  
Element Model ◽  
Numerical Results ◽  
Normal Contact ◽  
Interference Fit ◽  
Axial Load Capacity ◽  
Normal Contact Stiffness

This article describes the effect of the roughness size on the axial slip strength between the parts of shaft/hub joints with interference fit. The surface roughness was obtained from a turning process with different finishes (fine, medium and rough). A finite element modeling was developed, which uses a normal contact stiffness equivalent to the size of the surface roughness between the joint pieces to represent the real contact. In order to validate the numerical model, theoretical results of contactpressure and extraction force of the shaft/hub joint with smooth elements were compared with the corresponding numerical results obtained. The numerical results from studies that considered the size of the surface roughness showed that the axial load capacity of the joint decreased with larger roughness.

scholarly journals Tailorable and Repeatable Normal Contact Stiffness via Micropatterned Interfaces

2021 ◽  
Author(s):  
Jack Perris ◽  
Yang Xu ◽  
Mehmet E. Kartal ◽  
Nikolaj Gadegaard ◽  
Daniel Mulvihill
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Contact Stiffness ◽  
Element Model ◽  
Normal Contact ◽  
Square Wave ◽  
Surface Features ◽  
Normal Contact Stiffness ◽  
Low Levels

Abstract An approach to producing interfaces with tailored and repeatable normal contact stiffness using micropatterned surfaces is developed. A finite element model is first used to design square wave interfaces having a range of stiffnesses and these are fabricated in polycarbonate via a microfabrication process. Results demonstrate that the contact stiffnesses of the fabricated interfaces are both tailorable and repeatable. The approach can be broadened to other materials and is useful for applications requiring specified interface stiffness. Finally, even with these deterministic interfaces, we show that low levels of roughness on the surface features is sufficient to produce a load-dependent contact stiffness at lower loads. Therefore, tailorability is mostly applicable above this limit where total contact stiffness converges to a load-independent value.

scholarly journals Tailorable and Repeatable Normal Contact Stiffness via Micropatterned Interfaces

2021 ◽  
Vol 69 (3) ◽  
Author(s):  
Jack Perris ◽  
Yang Xu ◽  
Mehmet E. Kartal ◽  
Nikolaj Gadegaard ◽  
Daniel M. Mulvihill
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Contact Stiffness ◽  
Element Model ◽  
Normal Contact ◽  
Square Wave ◽  
Surface Features ◽  
Normal Contact Stiffness ◽  
Low Levels

Abstract An approach to producing interfaces with tailored and repeatable normal contact stiffness using micropatterned surfaces is developed. A finite element model is first used to design square wave interfaces having a range of stiffnesses, and these are fabricated in polycarbonate via a microfabrication process. Results demonstrate that the contact stiffnesses of the fabricated interfaces are both tailorable and repeatable. The approach can be broadened to other materials and is useful for applications requiring specified interface stiffness. Finally, even with these deterministic interfaces, we show that low levels of roughness on the surface features are sufficient to produce a load-dependent contact stiffness at lower loads. Therefore, tailorability is mostly applicable above this limit where total contact stiffness converges to a load-independent value. Graphic Abstract

scholarly journals Stiffness of Carpentry Connections – Numerical Modelling vs. Experimental Test

2015 ◽  
Vol 11 (2) ◽  
pp. 121-135
Author(s):  
Miloš Kekeliak ◽  
Jozef Gocál ◽  
Josef Vičan
Keyword(s):  
Surface Roughness ◽  
Numerical Model ◽  
Numerical Modelling ◽  
Contact Stiffness ◽  
Experimental Tests ◽  
Normal Contact ◽  
Study Results ◽  
Normal Contact Stiffness ◽  
Contact Surfaces ◽  
Mortise And Tenon

Abstract In this paper, numerical modelling of the traditional carpentry connection with mortise and tenon is presented. Numerical modelling is focused on its stiffness and the results are compared to results of experimental tests carried out by (Feio, 2005) [6]. To consider soft behaviour of wood in carpentry connections, which are related to its surface roughness and geometrical accuracy of the contact surfaces, the characteristics of the normal contact stiffness, determined experimentally, are introduced in the numerical model. Parametric study by means of numerical modelling with regard to the sensitivity of connection stiffness to contact stiffness is presented. Based on the study results, in conclusion there are presented relevant differences between the results of numerical modelling and experimental tests (Feio, 2005) [6].

scholarly journals Linear relationship of normal and tangential contact stiffness with load

2020 ◽  
Vol 476 (2243) ◽  
pp. 20200329
Author(s):  
K. S. Parel ◽  
R. J. Paynter ◽  
D. Nowell
Keyword(s):  
Surface Roughness ◽  
Linear Relationship ◽  
Normal Load ◽  
Contact Stiffness ◽  
Roughness Parameter ◽  
Image Correlation ◽  
Tangential Load ◽  
Normal Contact ◽  
Tangential Contact ◽  
Normal Contact Stiffness

Measurements with digital image correlation of normal and tangential contact stiffness for ground Ti-6Al-4V interfaces suggest a linear relationship between normal contact stiffness and normal load and a linear relationship between tangential contact stiffness and tangential load. The normal contact stiffness is observed approximately to be inversely proportional to an equivalent surface roughness parameter, defined for two surfaces in contact. The ratio of the tangential contact stiffness to the normal contact stiffness at the start of tangential loading is seen to be given approximately by the Mindlin ratio. A simple empirical model is proposed to estimate both the normal and tangential contact stiffness at different loads for a ground Ti-6Al-4V interface, on the basis of the equivalent surface roughness and the coefficient of friction.

scholarly journals Evolution Behavior Analysis of Normal Contact Stiffness of Fractal Surface under Loading and Unloading

2020 ◽  
Vol 38 (6) ◽  
pp. 1188-1197
Author(s):  
Kaian Liu ◽  
Yingqiang Xu ◽  
Zhenghai Wu ◽  
Li Xiao
Keyword(s):  
Fractal Dimension ◽  
Scale Parameter ◽  
Contact Stiffness ◽  
Element Model ◽  
Tangent Modulus ◽  
Fractal Surface ◽  
Normal Contact ◽  
Scale Parameters ◽  
Normal Contact Stiffness ◽  
Loading And Unloading

In order to analyze the evolution of normal contact stiffness under loading and unloading, an accurate elastic-plastic contact finite element model between rigid plane and fractal surface is established by introducing the equivalent metal matrix deformation in terms of the modified Weierstrass-Mandelbrot function. The effects of the fractal dimension, scale parameter, material properties on the normal contact stiffness were discussed. A method for evaluating the normal contact stiffness was proposed to analyze the evolution of the normal contact stiffness. Numerical simulation shows that there is a positive power function relationship between the normal contact stiffness and the load of fractal surface. Under the same load, at the fractal dimensions (D) of 2.4-2.7 and scale parameters (G) of 1.36×10-13-1.36×10-10 m, the loading normal contact stiffness increases with the increasing of fractal dimension and tangent modulus, but decreases with the increasing of scale parameter. The unloading normal contact stiffness increases with the material strengthening, and the variation amplitude is positively correlated with the fractal dimension, and negatively correlated with the scale parameters and tangent modulus.

One Method for Estimating Normal Contact Stiffness with Ra and Adhesion Rate

2013 ◽  
Vol 734-737 ◽  
pp. 2443-2450
Author(s):  
Peng Wang ◽  
Tian Yun Li ◽  
Xiang Zhu ◽  
Guo Xiong Pan
Keyword(s):  
Surface Roughness ◽  
Vibration Isolation ◽  
Contact Stiffness ◽  
Low Noise ◽  
Normal Contact ◽  
Surface Machining ◽  
Fractal Parameters ◽  
Normal Contact Stiffness ◽  
Adhesion Rate ◽  
The Cost

Based on the fractal contact theory, the model about the relation between normal contact stiffness and material properties as well as fractal parameters is established. Then by making use of the relation between fractal parameters and surface roughness, a new method for estimating the normal contact stiffness is put forward. The numerical results indicate that the contact stiffness increases as surface roughness decreases or adhesion rate increases. When the adhesion rate is constant, contact stiffness changes a little whileRa≥6.3μm, but the change is relatively bigger whenRa≤6.3μm. Considering both the cost of surface machining and the influence of contact stiffness on the whole system, the surface roughness is suggested to beRa=6.3μm. The results provide theoretical supports for vibration isolation analysis with gaskets and the process of low-noise construction.

scholarly journals Micromechanical modeling of the contact stiffness of an osseointegrated bone–implant interface

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Maria Letizia Raffa ◽  
Vu-Hieu Nguyen ◽  
Guillaume Haiat
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Bone Tissue ◽  
Contact Stiffness ◽  
Constitutive Law ◽  
Micromechanical Modeling ◽  
Fe Model ◽  
Periprosthetic Bone ◽  
Normal Contact ◽  
Bone Implant

Abstract Background The surgical success of cementless implants is determined by the evolution of the biomechanical properties of the bone–implant interface (BII). One difficulty to model the biomechanical behavior of the BII comes from the implant surface roughness and from the partial contact between bone tissue and the implant. The determination of the constitutive law of the BII would be of interest in the context of implant finite element (FE) modeling to take into account the imperfect characteristics of the BII. The aim of the present study is to determine an effective contact stiffness $$\left( {K_{c}^{\text{FEM}} } \right)$$KcFEM of an osseointegrated BII accounting for its micromechanical features such as surface roughness, bone–implant contact ratio (BIC) and periprosthetic bone properties. To do so, a 2D FE model of the BII under normal contact conditions was developed and was used to determine the behavior of $$K_{c}^{\text{FEM}}$$KcFEM. Results The model is validated by comparison with three analytical schemes based on micromechanical homogenization including two Lekesiz’s models (considering interacting and non-interacting micro-cracks) and a Kachanov’s model. $$K_{c}^{\text{FEM}}$$KcFEM is found to be comprised between 1013 and 1015 N/m3 according to the properties of the BII. $$K_{c}^{\text{FEM}}$$KcFEM is shown to increase nonlinearly as a function of the BIC and to decrease as a function of the roughness amplitude for high BIC values (above around 20%). Moreover, $$K_{c}^{\text{FEM}}$$KcFEM decreases as a function of the roughness wavelength and increases linearly as a function of the Young’s modulus of periprosthetic bone tissue. Conclusions These results open new paths in implant biomechanical modeling since this model may be used in future macroscopic finite element models modeling the bone–implant system to replace perfectly rigid BII conditions.

Finite Element Simulation of Tire-Rim Interface

1989 ◽  
Vol 17 (4) ◽  
pp. 305-325 ◽  
Author(s):  
N. T. Tseng ◽  
R. G. Pelle ◽  
J. P. Chang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Simulation ◽  
Contact Pressure ◽  
Element Model ◽  
Experimental Measurements ◽  
Inflation Pressure ◽  
Interference Fit ◽  
Element Simulation ◽  
Rubber Composite

Abstract A finite element model was developed to simulate the tire-rim interface. Elastomers were modeled by nonlinear incompressible elements, whereas plies were simulated by cord-rubber composite elements. Gap elements were used to simulate the opening between tire and rim at zero inflation pressure. This opening closed when the inflation pressure was increased gradually. The predicted distribution of contact pressure at the tire-rim interface agreed very well with the available experimental measurements. Several variations of the tire-rim interference fit were analyzed.

Finite Element Analysis of Tire/Rim Interface Forces Under Braking and Cornering Loads

1992 ◽  
Vol 20 (2) ◽  
pp. 83-105 ◽  
Author(s):  
J. P. Jeusette ◽  
M. Theves
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Contact Pressure ◽  
Element Model ◽  
Shear Stresses ◽  
Detailed Knowledge ◽  
Stress Distributions ◽  
Element Analysis ◽  
Plane Shear ◽  
Normal Contact

Abstract During vehicle braking and cornering, the tire's footprint region may see high normal contact pressures and in-plane shear stresses. The corresponding resultant forces and moments are transferred to the wheel. The optimal design of the tire bead area and the wheel requires a detailed knowledge of the contact pressure and shear stress distributions at the tire/rim interface. In this study, the forces and moments obtained from the simulation of a vehicle in stationary braking/cornering conditions are applied to a quasi-static braking/cornering tire finite element model. Detailed contact pressure and shear stress distributions at the tire/rim interface are computed for heavy braking and cornering maneuvers.

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