A novel technique for modeling friction behavior in knitted fabric simulation

Purpose Fabric-object friction force is a fundamental factor in cloth simulation. A large number of parameters influence the frictional properties of fabrics such as fabric structure, yarn structure, and inherent properties of component fibers. The purpose of this paper is to propose a novel technique for modeling fabric-object friction force in knitted fabric simulation based on the mass spring model. Design/methodology/approach In this technique, unlike other studies, distribution of friction coefficient over the fabric surface is not uniform and depends on the fabric structure. The main reason for considering non-uniform distribution is that in various segments of fabric, contact percent of fabric-object is different. Findings The proposed technique and common methods based on friction coefficient uniform distribution are used to simulate the frictional behavior of knitted fabrics. The results show that simulation error values for proposed technique and common methods are 2.7 and 9.4 percent as compared with the experimental result, respectively. Originality/value In the existing methods of the friction force modeling, the friction coefficient of fabric is assumed uniform. But this assumption is not correct because fabric does not have an isotropic structure. Thus in this study, the friction coefficient distribution is considered based on fabric structure to achieve more of realistic simulations.

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Experiment and simulation of friction coefficient of polyoxymethylene

Industrial Lubrication and Tribology ◽

10.1108/ilt-05-2016-0120 ◽

2018 ◽

Vol 70 (2) ◽

pp. 273-281 ◽

Cited By ~ 6

Author(s):

Xiaoshuang Xiong ◽

Lin Hua ◽

Xiaojin Wan ◽

Can Yang ◽

Chongyang Xie ◽

...

Keyword(s):

Mathematical Model ◽

Friction Coefficient ◽

Contact Pressure ◽

Friction Force ◽

Normal Load ◽

Fe Model ◽

Sliding Velocity ◽

Experiment Data ◽

Simulation Data ◽

Content Type

Purpose The purposes of this paper include studying the friction coefficient of polyoxymethylene (POM) under a broad range of normal load and sliding velocity; developing a mathematical model of friction coefficient of POM under a broad range of normal loads and sliding velocities; and applying the model to dynamic finite element (FE) analysis of mechanical devices containing POM components. Design/methodology/approach Through pin-on-disc experiment, the friction coefficient of POM in different normal loads and sliding velocities is investigated; the average contact pressure is between 5 and 15 Mpa and the sliding velocity is from 0.05 to 0.9 m/s. A friction algorithm is developed and embedded in the FE model to simulate the friction of POM in different normal loads and sliding velocities. Findings The friction coefficient of POM against steel declines with the increase of normal loads when the contact pressure is between 5 and 15 Mpa. The friction coefficient of POM against steel increases markedly when the sliding velocity is between 0.05 and 0.15 m/s, it decreases sharply between 0.15-0.45 m/s and then it stabilizes at high sliding velocity between 0.45 and 0.9 m/s. The friction coefficient of POM in different working operations has a significant effect on contact stress and shear stress. The simulation data and experiment data of POM friction force fit very well; therefore, it can be concluded that the friction algorithm and FE model are accurate. Originality/value The friction coefficient of POM under a broad range of normal loads and sliding velocities is investigated. The friction coefficient model of POM is established as a function of normal loads and sliding velocities in the dry sliding condition. A friction algorithm is developed and embedded in the FE model of the friction of POM. The mathematical model of the friction coefficient accurately agrees with the experiment data, and simulation data and experiment data of the POM friction force fit very well.

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High-temperature friction behavior of amorphous carbon coating in glass molding process

Friction ◽

10.1007/s40544-020-0452-6 ◽

2020 ◽

Author(s):

Kangsen Li ◽

Gang Xu ◽

Xiaobin Wen ◽

Jun Zhou ◽

Feng Gong

Keyword(s):

High Temperature ◽

Friction Coefficient ◽

Service Life ◽

Friction Force ◽

Amorphous Carbon ◽

Carbon Coating ◽

Contact Interface ◽

Molding Process ◽

Friction Behavior ◽

Glass Molding

AbstractIn the glass molding process, the sticking reaction and fatigue wear between the glass and mold hinder the service life and functional application of the mold at the elevated temperature. To improve the chemical inertness and anti-friction properties of the mold, an amorphous carbon coating was synthesized on the tungsten carbide-cobalt (WC–8Co) substrate by magnetron sputtering. The friction behavior between the glass and carbon coating has a significant influence on the functional protection and service life of the mold. Therefore, the glass ring compression tests were conducted to measure the friction coefficient and friction force of the contact interface between the glass and amorphous carbon coating at the high temperature. Meanwhile, the detailed characterization of the amorphous carbon coating was performed to study the microstructure evolution and surface topography of the amorphous carbon coating during glass molding process by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Ramon spectroscopy, and atomic force microscope (AFM). The results showed that the amorphous carbon coating exhibited excellent thermal stability, but weak shear friction strength. The friction coefficient between the glass and coating depended on the temperature. Besides, the service life of the coating was governed by the friction force of the contact interface, processing conditions, and composition diffusion. This work provides a better understanding of the application of carbon coatings in the glass molding.

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Rolling-Friction Behavior of Sub-Micron Polystyrene-Sphere Arrays under Very Light Loads

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.321-324.174 ◽

2013 ◽

Vol 321-324 ◽

pp. 174-178

Author(s):

Jiao Qu ◽

Shi Rong Ge

Keyword(s):

Friction Coefficient ◽

Friction Force ◽

Self Assembly ◽

Sliding Friction ◽

Rolling Friction ◽

Polystyrene Sphere ◽

Si Substrate ◽

Friction Behavior ◽

Layer Film ◽

Colloidal Spheres

The uniform sub-micron colloidal spheres were arrayed on the surface of a Si substrate via self-assembly to forming a sphere-layer film (monolayer), with emphasis on the application of rolling friction in the presence of rolling spheres on the surface of micro- or nano-equipment. It was found that the arrayed spheres on the substrate are mobile arising from rolling, and they can significantly reduce the friction force through changing the sliding friction to rolling one, thus exhibiting a smaller friction coefficient value than that of pure substrate. On the other hand, the elastic deformation of polystyrene (PS) spheres also contributes to the reduced friction force. In the absence of lubricant, the optimal friction coefficient of sphere-layer film was found to be 0.059 at the load of 3500 µN, at which the friction force of sphere-layer film was only 68% that of substrate. The friction coefficient of sphere-layer film decreases with increasing the applied load up to 3500 µN, followed by an increase with a further enhanced load, which has been ascribed to the transition from elastic contact to plastic one.

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Study on high-temperature wear and mechanism of Al-Si/graphite composites prepared by the die-casting process

Industrial Lubrication and Tribology ◽

10.1108/ilt-10-2019-0454 ◽

2020 ◽

Vol 72 (10) ◽

pp. 1153-1158 ◽

Cited By ~ 1

Author(s):

Yafei Deng ◽

Xiaotao Pan ◽

Guoxun Zeng ◽

Jie Liu ◽

Sinong Xiao ◽

...

Keyword(s):

Friction Coefficient ◽

Wear Rate ◽

Peer Review ◽

Die Casting ◽

Casting Machine ◽

Injection Pressure ◽

Casting Process ◽

Matrix Alloy ◽

Content Type ◽

The Matrix

Purpose This paper aims to improve the tribological properties of aluminum alloys and reduce their wear rate. Design/methodology/approach Carbon is placed in the model at room temperature, pour 680°C of molten aluminum into the pressure chamber, and then pressed it into the mold containing carbon felt through a die casting machine, and waited for it to cool, which used an injection pressure of 52.8 MPa and held the same pressure for 15 s. Findings The result indicated that the mechanical properties of matrix and composite are similar, and the compressive strength of the composite is only 95% of the matrix alloy. However, the composite showed a low friction coefficient, the friction coefficient of Gr/Al composite is only 0.15, which just is two-third than that of the matrix alloy. Similarly, the wear rate of the composite is less than 4% of the matrix. In addition, the composite can avoid severe wear before 200°C, but the matrix alloy only 100°C. Originality/value This material has excellent friction properties and is able to maintain this excellent performance at high temperatures. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0454/

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Relationship between the real contact behavior and tribological characteristics of cotton fabric

Friction ◽

10.1007/s40544-020-0398-8 ◽

2020 ◽

Author(s):

Rongxin Chen ◽

Jiaxin Ye ◽

Wei Zhang ◽

Jiang Wei ◽

Yan Zhang ◽

...

Keyword(s):

Friction Coefficient ◽

Contact Area ◽

Dynamic Change ◽

Tribological Characteristics ◽

Real Contact Area ◽

Cotton Fibers ◽

Friction Behavior ◽

Contact Behavior ◽

The Real ◽

Real Contact

Abstract The tribological characteristics of cotton fibers play an important role in engineering and materials science, and real contact behavior is a significant aspect in the friction behavior of cotton fibers. In this study, the tribological characteristics of cotton fibers and their relationship with the real contact behavior are investigated through reciprocating linear tribotesting and real contact analysis. Results show that the friction coefficient decreases with a general increase in load or velocity, and the load and velocity exhibit a co-influence on the friction coefficient. The dynamic change in the real contact area is recorded clearly during the experiments and corresponds to the fluctuations observed in the friction coefficient. Moreover, the friction coefficient is positively correlated with the real contact area based on a quantitative analysis of the evolution of friction behavior and the real contact area at different loads and velocities. This correlation is evident at low velocities and medium load.

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Effect of shape/size and distribution of microgeometries of textures on tribo-performance of crankpin bearing

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1177/13506501211010552 ◽

2021 ◽

pp. 135065012110105

Author(s):

Nguyen Van Liem ◽

Wu Zhenpeng ◽

Jiao Renqiang

Keyword(s):

Friction Coefficient ◽

Friction Force ◽

Contact Force ◽

Distribution Density ◽

Hydrodynamic Lubrication ◽

Operating Conditions ◽

Asperity Contact ◽

Combined Model ◽

Obvious Effect ◽

Area Density

The effect of the shape/size and distribution of microgeometries of textures on improving the tribo-performance of crankpin bearing is proposed. Based on a combined model of the slider-crank mechanism dynamic and hydrodynamic lubrication, the distribution density, area density, and shape of spherical textures, square-cylindrical textures, wedge-shaped textures, and a hybrid between spherical texture and square-cylindrical texture on the crankpin bearing's tribo-performance are investigated under different operating conditions of the engine. The tribological characteristic of the crankpin bearing is then evaluated via the indexes of the oil film pressure p, asperity contact force, friction force, and friction coefficient of the crankpin bearing. The research results show that the distribution density with n = 12 and m = 6, and area density with α = 30% of various microtextures have an obvious effect on ameliorating the crankpin bearings tribo-performance. Concurrently, at the mixed lubrication region, the shape of the square-cylindrical texture on improving the tribo-performance is better than the other shapes of the spherical texture, wedge-shaped texture, and spherical and square-cylindrical texture. Particularly, all the average values of the asperity contact force, friction force, and friction coefficient with a square-cylindrical texture are significantly reduced by 14.6%, 19.5%, and 34.5%, respectively, in comparison without microtextures. Therefore, the microtextures of the spherical texture applied on the bearing surface can contribute to enhance the durability and decrease the friction power loss of the engine.

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An improved nonlinear model considering relative velocity for the friction behavior between untwisted glass-fiber tow and roller

Textile Research Journal ◽

10.1177/00405175211030877 ◽

2021 ◽

pp. 004051752110308

Author(s):

Yang Liu ◽

Zhong Xiang ◽

Xiangqin Zhou ◽

Zhenyu Wu ◽

Xudong Hu

Keyword(s):

Friction Coefficient ◽

Glass Fiber ◽

Relative Velocity ◽

Friction Model ◽

Woven Fabric ◽

Test Results ◽

Application Process ◽

Friction Behavior ◽

Improved Model

Friction between the tow and tool surface normally happens during the tow production, fabric weaving, and application process and has an important influence on the quality of the woven fabric. Based on this fact, this paper studied the influence of tension and relative velocity on the three kinds of untwisted-glass-fiber tow-on-roller friction with a Capstan-based test setup. Furthermore, an improved nonlinear friction model taking both tension and velocity into account was proposed. According to statistical test results, firstly, the friction coefficient was found to be positively correlated with tension and relative velocity. Secondly, tension and velocity were complementary on the tow-on-roller friction behavior, with neither being superior to the other. Thirdly, an improved model was found to present well the nonlinear characteristics between friction coefficient and tension and velocity, and predicational results of the model were found to agree well with the observations from Capstan tests.

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The parameter identification model considering both geometric parameters and joint stiffness

Industrial Robot the international journal of robotics research and application ◽

10.1108/ir-11-2018-0223 ◽

2019 ◽

Vol 47 (1) ◽

pp. 76-81

Author(s):

Jing Bai ◽

Le Fan ◽

Shuyang Zhang ◽

Zengcui Wang ◽

Xiansheng Qin

Keyword(s):

Parameter Identification ◽

Industrial Robot ◽

Joint Stiffness ◽

Geometric Parameters ◽

Least Square ◽

Experimental Result ◽

Positional Accuracy ◽

Content Type ◽

The Absolute ◽

Identification Model

Purpose Both geometric and non-geometric parameters have noticeable influence on the absolute positional accuracy of 6-dof articulated industrial robot. This paper aims to enhance it and improve the applicability in the field of flexible assembling processing and parts fabrication by developing a more practical parameter identification model. Design/methodology/approach The model is developed by considering both geometric parameters and joint stiffness; geometric parameters contain 27 parameters and the parallelism problem between axes 2 and 3 is involved by introducing a new parameter. The joint stiffness, as the non-geometric parameter considered in this paper, is considered by regarding the industrial robot as a rigid linkage and flexible joint model and adds six parameters. The model is formulated as the form of error via linearization. Findings The performance of the proposed model is validated by an experiment which is developed on KUKA KR500-3 robot. An experiment is implemented by measuring 20 positions in the work space of this robot, obtaining least-square solution of measured positions by the software MATLAB and comparing the result with the solution without considering joint stiffness. It illustrates that the identification model considering both joint stiffness and geometric parameters can modify the theoretical position of robots more accurately, where the error is within 0.5 mm in this case, and the volatility is also reduced. Originality/value A new parameter identification model is proposed and verified. According to the experimental result, the absolute positional accuracy can be remarkably enhanced and the stability of the results can be improved, which provide more accurate parameter identification for calibration and further application.

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Retroperitoneal lateral lumbar interbody fusion with titanium threaded fusion cages

Journal of Neurosurgery Spine ◽

10.3171/spi.2002.96.1.0050 ◽

2002 ◽

Vol 96 (1) ◽

pp. 50-55 ◽

Cited By ~ 4

Author(s):

Christopher E. Wolfla ◽

Dennis J. Maiman ◽

Frank J. Coufal ◽

James R. Wallace

Keyword(s):

Interbody Fusion ◽

Lumbar Fusion ◽

Fusion Rate ◽

Lumbar Interbody Fusion ◽

Anterior Longitudinal Ligament ◽

Content Type ◽

Single Cage ◽

Novel Technique ◽

Methodological Problems ◽

Fine Print

Object. Intertransverse arthrodesis in which instrumentation is placed is associated with an excellent fusion rate; however, treatment of patients with symptomatic nonunion presents a number of difficulties. Revision posterior and traditional anterior procedures are associated with methodological problems. For example, in the latter, manipulation of the major vessels from L-2 to L-4 may be undesirable. The authors describe a method for performing retroperitoneal lumbar interbody fusion (LIF) in which a threaded cage is placed from L-2 through L-5 via a lateral trajectory, and they also detail a novel technique for implanting a cage from L-5 to S-1 via an oblique trajectory. Although they present data obtained over a 2-year period in the study of 15 patients, the focus of this report is primarily on describing the surgical procedure. Methods. The lateral lumbar spine was exposed via a standard retroperitoneal approach. Using the anterior longitudinal ligament as a landmark, the L2–3 through L4–5 levels were fitted with instrumentation via a true lateral trajectory; the L5—S1 level was fitted with instrumentation via an oblique trajectory. A single cage was placed at each instrumented level. Fifteen symptomatic patients in whom previous lumbar fusion had failed underwent retroperitoneal LIF. Thirty-eight levels were fitted with instrumentation. There have been no instrumentation-related failures, and fusion has occurred at 37 levels during the 2-year postoperative period. Conclusions. The use of retroperitoneal LIF in which threaded fusion cages are used avoids the technical difficulties associated with repeated posterior procedures. In addition, it allows L2—S1 instrumentation to be placed anteriorly via a single surgical approach. This construct has been shown to be biomechanically sound in animal models, and it appears to be a useful alternative for the management of failed multilevel intertransverse arthrodesis.

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