Numerical Simulation of the Fatigue Process in the Contact Area of Spur Gears

2009 ◽  
Author(s):  
S. Glodez ◽  
J. Flasker ◽  
Z. Ren
Keyword(s):  
Numerical Simulation ◽  
Contact Area ◽  
Spur Gears ◽  
Fatigue Process

Numerical Simulation of Digital Microfluidics Based on Electro-Dynamic Model

2012 ◽  
Vol 2 (3) ◽  
pp. 14-23
Author(s):  
Liguo Chen ◽  
Mingxiang Ling ◽  
Deli Liu
Keyword(s):  
Numerical Simulation ◽  
Simulation Model ◽  
Contact Line ◽  
Contact Area ◽  
Digital Microfluidics ◽  
Phase Contact ◽  
Electrowetting On Dielectric ◽  
Three Phase ◽  
Internal Mechanism ◽  
Contact Domain

Aiming at the doubt and divarication about the internal mechanism of electrowetting on dielectric (EWOD) in digital microfluidics, the authors attempted to explain the internal mechanism of EWOD through electro-dynamic-based numerical simulation model. First, the boundary conditions for the governing equation were found. Then the influence of mesh number on simulation results was analyzed and feasibility of the simulation model was verified by comparing numerical results with theoretical ratiocination. Finally, they compared the electro-dynamic actuation force acting on the surface of droplet on three digital microfluidic structures, which have the same three-phase contact line but different area of contact domain. Analytical results showed that electro-dynamic force generated solely by the accumulation of induced charges in contact domain was three times larger than that generated by three-phase contact line. Induced charges accumulated on both three-phase contact line and contact area of droplet gave the contribution to EWOD, but contact area played a major role in the change of contact angle of droplet.

scholarly journals An analysis of effective thermal conductivity of heterogeneous materials

2014 ◽  
Vol 14 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Guocheng Zhu ◽  
Dana Kremenakova ◽  
Yan Wang ◽  
Jiri Militky ◽  
Funda Buyuk Mazari
Keyword(s):  
Thermal Conductivity ◽  
Numerical Simulation ◽  
Thermal Property ◽  
Effective Thermal Conductivity ◽  
Contact Area ◽  
Heterogeneous Materials ◽  
Inclusion Size ◽  
Analytical Models ◽  
Important Index ◽  
Inclusion Shape

Abstract Effective thermal conductivity (ETC) is a very important index for evaluating the thermal property of heterogeneous materials, which include more than two different kinds of materials. Several analytical models were proposed for predicting the ETC of heterogeneous materials, but in some cases, these models cannot provide very accurate predictions. In this work, several analytical models and numerical simulations were studied in order to investigate the differences among them. In addition, some factors which would influence the ETC of heterogeneous materials were investigated by numerical simulation. The results demonstrated that the numerical simulation can provide very accurate prediction, indicated that different analytical models should be selected to predict specific problems based on their assumptions, and suggested that more variables need to be considered in order to improve these analytical models, such as inclusion shape, inclusion size, distribution of inclusions and contact area. Besides, numerical method could be an effective and reliable way to obtain the ETC of heterogeneous materials with any kind of complicated structures.

scholarly journals Диссипация механической энергии в осциллирующем адгезионном контакте между жестким индентором и эластомером

2020 ◽  
Vol 46 (21) ◽  
pp. 44
Author(s):  
Я.А. Ляшенко ◽  
В.Л. Попов
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Direct Observation ◽  
Contact Area ◽  
Indentation Depth ◽  
Adhesive Contact ◽  
Critical Value ◽  
Chemical Inhomogeneity ◽  
Maximum Indentation Depth

A model of hysteresis in an adhesive contact under oscillating loading is proposed, based on the chemical inhomogeneity of the indenter surface. Results of numerical simulation are compared with experimental data obtained with a setup allowing direct observation of the dynamics of contact area. It is shown that the hysteresis almost disappears if the amplitude of the oscillating load is smaller than a critical value depending on the maximum indentation depth.

Numerical study of a blind bolted connection between an aluminum bridge deck and steel girders

2021 ◽  
Author(s):  
Soufiane el Ogri ◽  
Charles-Darwin Annan ◽  
Pampa Dey
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Contact Zone ◽  
Contact Area ◽  
Bridge Deck ◽  
Numerical Study ◽  
Highway Bridge ◽  
Steel Girders ◽  
Bolted Connection ◽  
Extensive Numerical Simulation

<p>This article concerns the behaviour of two blind bolt types, Ajax One side and Blind Oversize Mechanically (BOM), used to connect a multi-void aluminum bridge deck on its supporting steel girders. An extensive numerical simulation by FEM was performed to evaluate the connection behaviour against the Canadian Highway Bridge Design standard CSA S6-19. The main objective was to examine the assembly against fretting and quantify its impact at the contact zone over several load cycles. A special numerical model was developed for the prediction of fretting, and validated with analytical results and other observations reported in the literature. The model was used to analyze the fretting for each bolt at the surface of contact between the bolt head and the aluminum plate. Results of the study revealed that the blind bolts will lead to a few micrometers of wear, while for the standard bolt, a probable crack developments associated with minor wear may occur at the contact area.</p>

Experimental and Numerical Simulation Study of Simultaneous Toothing of Spur Gears by Press-Rolling Process

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Liviu Nistor ◽  
Adriana Neag ◽  
Ionut Marian ◽  
Dan Frunza
Keyword(s):  
Numerical Simulation ◽  
Continuous Flow ◽  
Spur Gear ◽  
Rolling Process ◽  
Experimental Investigations ◽  
Spur Gears ◽  
Element Analysis ◽  
3D Finite Element ◽  
Gear Geometry ◽  
Experimental Trials

In this paper, the cold simultaneous toothing of spur gears has been investigated. This method can be described as a press-rolling process. The influence of gear geometry such as teeth number and the deformation mechanism was investigated by 3D finite-element analysis using forge® software in terms of teeth forming and forming loads evolution. Based on these simulations, the experimental investigations were carried out to obtain a spur gear form with the good quality, using several billet dimensions. The experimental trials and simulations conducted for the spur gear (z = 23 teeth and m = 1.5 mm) showed premises to continuous flow lines formation at the base of the teeth. The maximum pressing force results from the numerical simulation agree with the experimental maximum force recorded.

scholarly journals Numerical Simulation of Galvanic Corrosion between Carbon Steel and Low Alloy Steel in a Bolted Joint

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Rachid Radouani ◽  
Younes Echcharqy ◽  
Mohamed Essahli
Keyword(s):  
Numerical Simulation ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Alloy Steel ◽  
Contact Area ◽  
Galvanic Corrosion ◽  
Research Work ◽  
Steel Structures ◽  
Low Alloy Steel ◽  
End Plate

The galvanic corrosion of a bolt joint combining carbon steel end plate and low alloy steel bolt was investigated electrochemically in a 1 M HCl solution. The corrosion parameters of the joint components were used for numerical simulation using Comsol Multiphysics software to analyze the galvanic corrosion behavior at the contact zone between the head bolt and the end plate. In this research work we evaluate the variation of the corrosion rate in the steel end plate considered as the anode, in order to determine the lifetime of the bolted assembly used in steel structures. Three materials (20MnCr5, 42CrMo4, and 32CrMoV13) and three bolts (M12, M16, and M20) were tested in two thicknesses of electrolyte 1 M HCl (e = 1 mm, e = 20 mm). It is found that the corrosion rate of the anode part (end plate) is higher for 32CrMoV13 materials and it increases if both diameter of the bolt and thickness of the electrolyte increase (Cr(M20) > Cr(M16) > Cr(M12) and Cr(e = 20 mm) > Cr(e = 1 mm)). This corrosion rate is higher in the contact area between the bolt head and the end plate, and it decreases if we move away from this contact area.

scholarly journals Optimization for U-Shaped Steel Support in Deep Tunnels under Coupled Static-Dynamic Loading

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Yujun Zuo ◽  
Jian Wang ◽  
Longjun Dong ◽  
Weiwei Shu ◽  
Meilu Yu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Dynamic Loading ◽  
Contact Area ◽  
Simulation Method ◽  
Surrounding Rock ◽  
Perturbation Equation ◽  
Lateral Stress ◽  
High Geostress ◽  
The Stability ◽  
Tunnel Instability

With the effects of high geostress and intensive dynamic disturbances in deep mining, the stability and safety of tunnels are seriously affected. The optimization for U-shaped steel support is of vital significance and can solve the problems of cost reduction and tunnel instability. Based on the perturbation equation, a coupled formula for U-shaped steel and the surrounding rock mass was proposed to evaluate the practical stability of a U-shaped steel support. Through a numerical simulation method, the characteristics of U-shaped steel support can be obtained under coupled static-dynamic loading. Furthermore, the field test was carried out and compared with the numerical simulation, which was discussed. The results show that there will be a stress concentration when the contact area is small. In addition, the concentrated stress will release with the increase in contact area. With the increase in the lateral stress coefficient, the deformation exhibits a downward trend under static loading, indicating that the lateral stress is the dominant force driving the deep geostress activity. The support requirement of this section of surrounding rock can be satisfied by a U-shaped steel group with 1.5 m spacing under dynamic disturbance.

Numerical Simulation and Stability Analysis of Thin Flexible Micro Film for Thermotunneling Application

2012 ◽  
Author(s):  
Eniko T. Enikov ◽  
Mahdi Ganji
Keyword(s):  
Numerical Simulation ◽  
Contact Area ◽  
Numerical Solutions ◽  
Thermionic Emission ◽  
Hot Electrons ◽  
Beam Equation ◽  
Practical Implementation ◽  
Beam Model ◽  
Small Current ◽  
Thermo Electric

Combined thermionic emission and tunneling of hot electrons (thermo-tunneling) has emerged as a potential new solidstate cooling technology. Practical implementation of thermo-tunneling, however, requires the formation of a nanometer-sized gap spanning macroscopically significant surfaces. Thermo-tunneling is a term used to describe combined emission of hot electrons (thermionic emission) and tunneling of electrons through a narrow potential barrier between two surfaces (field emission). Thermo-tunneling of hot electrons across a few-nanometer gap has application to vacuum electronics, flat panel displays, and holds great potential in thermo-electric cooling and energy generation. Development of new thermo-tunneling applications requires creation of a stable nanometer gap between two surfaces. This presentation is focused on our effort to investigate the stability of the the thin flexible structure under electrostatic and lorenz forces opposing each other. In this presentation, we report the result of numerical simulation with some mathematical simplifications. The mathematical model used for the numerical simulation is well studied in the literature. Using forth-order partial differential beam equation, we studied the steady state solutions of the thermo-tunneling beam model using Galerkin method. Essential output parameters of the model include a central contact area measured by its length (delta) and the thermo-tunneling current. Both parameters are determined as a function of the externally applied external potential and magnetic field. Numerical solutions of the model show two possible operating modes: (1) symmetric deformation with negligibly small current; and (2) asymmetric mode where the B-field controls the current and contact area. Under practical values for the externally applied magnetic and electric fields, it has been shown that the second mode is only possible for electrode with very low work functions, e.g. below 0.5 eV. Therefore, novel materials such as Diamond-like carbon films are likely to be essential in thermo-tunneling applications.

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