Journal articles: 'Directional friction'

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Tiwari, A., L. Dorogin, B. Steenwyk, A. Warhadpande, M. Motamedi, G. Fortunato, V. Ciaravola, and B. N. J. Persson. "Rubber friction directional asymmetry." EPL (Europhysics Letters) 116, no. 6 (December 1, 2016): 66002. http://dx.doi.org/10.1209/0295-5075/116/66002.

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Qi, Yexiong, Waqar Iqbal, and Yaming Jiang. "Study on the Multi-Directional Static Friction Properties of High Performance Yarns." Fibres & Textiles in Eastern Europe 151, no. 3 (October 1, 2022): 111–15. http://dx.doi.org/10.2478/ftee-2022-0029.

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Abstract To further optimise the bullet-proof performance of textile reinforced composites, multi-directional friction tests of aramid and ultra-high molecular weight polyethylene (UHMWPE) yarns were carried out by the slope method. The influence of the included angle between the high-performance yarns on the static friction coefficient for aramid and UHMWPE yarns was studied by measuring the friction coefficient. The relationship between the static friction coefficient and the included angle among the high-performance yarns was discussed. The results showed that the friction coefficient of aramid yarns was higher than that of UHMWPE yarns. Especially, at the same included angle between high-performance yarns, the static frictional coefficient of aramid yarns is 50% higher than that of UHMWPE yarns. In accordance with expectations, the static friction coefficient decreases with the increased included angle between high-performance yarns, and the included angle of high-performance yarns changes from 0º to 90º. The trend of rapid decline appeared when the included angle between high-performance yarns changed from 0º to 15º. For the actual result, the static friction coefficient of aramid and UHMWPE yarns is less than 0.3, which needs to be improved to increase the bullet-proof performance of textile composites.

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Stosiak, Michał, Mykola Karpenko, Adam Deptuła, Kamil Urbanowicz, Paulius Skačkauskas, Rafał Cieślicki, and Anna Małgorzata Deptuła. "Modelling and Experimental Verification of the Interaction in a Hydraulic Directional Control Valve Spool Pair." Applied Sciences 13, no. 1 (December 29, 2022): 458. http://dx.doi.org/10.3390/app13010458.

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This study examined the impact of mechanical oscillation on a hydraulic directional control valve. Particular attention was paid to the oscillating movement of the spool of the hydraulic directional control valve resulting from this impact. Different models of fluid and mixed friction were considered. The models analysed accounted for the relative movement of the directional control valve body and the fact that it is kinematically excited by external mechanical oscillations. It was observed that the mixed friction model, where the frictional force is considered to be the sum of molecular forces acting in micro-areas of contact and drag forces in the fluid, was the best for describing the movement of the spool for a specific spool oscillation frequency. This model yielded significantly more consistency between the simulated and experimental results than the classic fluid friction model.

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Jaculli, Marcelo A., José Ricardo P. Mendes, and Kazuo Miura. "Dynamic buckling with friction inside directional wells." Journal of Petroleum Science and Engineering 153 (May 2017): 145–56. http://dx.doi.org/10.1016/j.petrol.2017.03.040.

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Ezazshahabi, Nazanin, Masoud Latifi, and Mohammad Amani Tehran. "Analysis of Frictional Behavior of Woven Fabrics by a Multi-directional Tactile Sensing Mechanism." Journal of Engineered Fibers and Fabrics 10, no. 3 (September 2015): 155892501501000. http://dx.doi.org/10.1177/155892501501000307.

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The frictional property of woven fabrics is one of the prominent surface characteristics which influence the performance of fabrics in a variety of applications. In this paper a novel methodology and instrument is proposed to measure the tactile force between fabric and simulated skin in different directions, and the obtained data are used for assessing fabric frictional property. In this regard, nine groups of woven fabrics consisting of three weave structures and three different weft densities were tested. By fitting the data with a proper equation, the tactile force in terms of fabric direction was predicted. The mentioned equation is also utilized for estimation of frictional behavior of fabric in various directions. Moreover, a single, new parameter called “frictional energy” is defined which has the ability to properly quantify the fabric frictional behavior. Statistical analysis of results reveals that the effect of weave structure and weft density is significant on the fabric friction. Being aware of the effect of fabric construction on friction is a guide for selecting the suitable fabric for various end uses.

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Chu, L., X. Cui, K. Zhang, T. F. Fwa, and S. Han. "Directional Skid Resistance Characteristics of Road Pavement: Implications for Friction Measurements by British Pendulum Tester and Dynamic Friction Tester." Transportation Research Record: Journal of the Transportation Research Board 2673, no. 10 (June 4, 2019): 793–803. http://dx.doi.org/10.1177/0361198119851453.

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The British pendulum tester (BPT) and the dynamic friction tester (DFT) are commonly used to evaluate the polishing effect of traffic on pavement skid resistance. The present study was conducted to answer two questions: (i) whether the directional moving traffic action results in significant directional differences in skid resistance of the pavement, and (ii) if so, whether BPT and DFT are effective tools for evaluating the skid resistance performance of polished pavements with significant directional skid resistance characteristics. Five in-service pavement sections with different degrees of polishing were examined in this study. The following findings were obtained from the study: (a) There were statistically significant differences between the longitudinal and transverse skid resistance of the polished pavements tested; (b) there were no statistically significant differences between the longitudinal and transverse skid resistance of the newly paved unpolished pavement tested; (c) BPT was able to differentiate the directional skid resistance differences of the polished pavements tested; and (d) DFT was unable to differentiate the directional skid resistance differences of the polished pavements tested. DFT produces one skid resistance value for a circular path at each test point. The test results found that DFT over-estimated the traffic-direction skid resistance of in-service pavements. The over-estimation errors ranged from 0.001 to 0.023 DFT units, and the corresponding percent errors were from 0.4% to 11.1%. This finding suggests that the over-estimation effect of skid resistance directionality of polished pavements on DFT measurements should be recognized in pavement skid resistance evaluation and pavement safety studies.

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Putignano, Carmine, Giuliano Parente, Francisco Josè Profito, Caterina Gaudiuso, Antonio Ancona, and Giuseppe Carbone. "Laser Microtextured Surfaces for Friction Reduction: Does the Pattern Matter?" Materials 13, no. 21 (October 31, 2020): 4915. http://dx.doi.org/10.3390/ma13214915.

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Frictional performances of different textures, including axisymmetric and directional patterns, have been tested in the mixed and the hydrodynamic lubrication regimes. Experimental results, corroborated by numerical simulations, show that the leading parameter is the geometrical pattern void ratio since a large number of dimples offers, at low speed, a trap for debris whereas, at high speed, due to the flow expansion in each micro-hole, fosters a fluid pressure drop, the consequent insurgence of micro-cavitation and, ultimately, the reductions of the shear stresses. Furthermore, in this paper, it is shown that, by means of directional textures, equivalent hydrodynamic wedges can be built up, thus establishing different friction performances depending on the flow direction.

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Wang, Wen’an, Zhiqi Liu, and Dongliang Chen. "Influence of different oil flow directions on the friction performance of asymmetric structures in heavy load hydraulic friction pairs." AIP Advances 13, no. 1 (January 1, 2023): 015028. http://dx.doi.org/10.1063/5.0137503.

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Textures have obvious anti-friction and anti-wear effects, but effective textures often have complex and asymmetric characteristics. Because of the texture’s directional lubrication effect and fluid diode effect, different oil flow directions influence the friction reduction effect of asymmetric texture. Simulations and test methods are used to characterize these effects, and the friction coefficient and wear amount are used as evaluation methods to determine the optimal oil flow direction of asymmetric textures. The results show that an appropriate oil flow direction can significantly change the texture’s friction-reducing ability. The friction reduction efficiency of the texture is highest when the angle between the oil flow direction and the inflow edge of the texture is 60°–90°. When the angle between the oil flow direction and the inflow edge of the texture is 0°–30°, the texture’s anti-friction effect and efficiency are weakened.

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Abed, Dana, Jafar Al Thawabteh, Yazan Alzubi, Jamal Assbeihat, and Eid Al-Sahawneh. "Influence of Earthquake Parameters on the Bi-directional Behavior of Base Isolation Systems." Civil Engineering Journal 8, no. 10 (October 1, 2022): 2038–52. http://dx.doi.org/10.28991/cej-2022-08-10-02.

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The introduction and development of the base isolation systems, especially the friction isolator device, were done recently to improve the capacity of adaptive behavior. The efficiency of multi-phase friction pendulums comes from their complexity, which helps reduce the structural responses and enhance structures' energy dissipation under lateral loads. Nevertheless, the influence of various earthquakes' properties on the behavior of base-isolation systems subjected to bi-directional seismic loading is still unclear. Hence, further research and studies regarding the behavior and capability of these systems under bi-directional loading are still necessary before incorporating this device in real-life practical applications. Therefore, this paper is intended to investigate the bi-directional behavior of the friction isolator subjected to various ground motion records. In order to do so, different versions of the friction pendulum system are selected and compared within the study context. Generally, the study's results have shown that the behavior of the friction isolator is highly dependent on low values of the PGA/PGV ratio. Besides, pulse-like earthquakes considerably impact the response of the isolator compared to non-pulse-like ones. Doi: 10.28991/CEJ-2022-08-10-02 Full Text: PDF

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Rawat, Aruna, Naseef Ummer, and Vasant Matsagar. "Performance of bi-directional elliptical rolling rods for base isolation of buildings under near-fault earthquakes." Advances in Structural Engineering 21, no. 5 (August 25, 2017): 675–93. http://dx.doi.org/10.1177/1369433217726896.

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Rolling base isolation system provides effective isolation to the structures from seismic base excitations by virtue of its low frictional resistance. Herein, dynamic analysis of flexible-shear type multi-storey building mounted on orthogonally placed elliptical rolling rod base isolation systems subjected to bi-directional components of near-fault earthquake ground motions is presented. The orthogonally placed rods would make it possible to resist the earthquake forces induced in the structure in both the horizontal directions. The curved surface of these elliptical rods has a self-restoring capability due to which the magnitude of peak isolator displacement and residual displacement is reduced. The roughness of the tempered curved surface of the rollers dissipates energy in motion due to frictional damping. The seismic performance of the multi-storey building mounted on the elliptical rolling rod base isolation system is compared with that mounted on the sliding pure-friction and cylindrical rolling rod systems. Parametric studies are conducted to examine the behavior of the building for different superstructure flexibilities, eccentricities of the elliptical rod, and coefficients of friction. It is concluded that the elliptical rolling rod base isolation system is effective in mitigation of damaging effects of the near-fault earthquake ground motions in the multi-storey buildings. Even under the near-fault earthquake ground motions, the base-isolated building mounted on the elliptical rolling rods shows considerable reduction in seismic response. The isolator displacement with the elliptical rolling rod base isolation system is less in comparison to the pure-friction and cylindrical rolling rod systems.

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11

Elgibaly, Ahmed A., Mohammed Shehata Farhat, Eric W. Trant, and Mohammed Kelany. "A study of friction factor model for directional wells." Egyptian Journal of Petroleum 26, no. 2 (June 2017): 489–504. http://dx.doi.org/10.1016/j.ejpe.2016.07.004.

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Kim, D. H., B. M. Kim, Y. Lee, and B. H. Min. "Friction characteristics for surface finish and the stoning direction of stamping dies." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 216, no. 4 (April 1, 2002): 531–42. http://dx.doi.org/10.1243/0954405021520229.

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This paper investigates the combined effects of parameters such as die surface finish, die stoning direction, contact pressure and draw speed on the resulting friction coefficient. The study shows the correlation between the artificial neural network (ANN) and the design of experiments (DOE). The ANN and the DOE have been implemented for minimizing the friction coefficient and for investigating the effect of the parameters in the straight pulling friction test effectively. The experiments were run in random order with at least three replications. It was found that directional stoning orthogonal to the pulling direction lowers the friction more than directional stoning parallel to the pulling direction using die material FCD55 and sheet material SPCEN.

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13

Eigoli, A. Kamali, and GR Vossoughi. "Dynamic analysis of vibration-driven systems moving based on frictional locomotion principles." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 226, no. 7 (November 23, 2011): 1787–99. http://dx.doi.org/10.1177/0954406211428239.

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In this article, we investigate the dynamic analysis of vibration-driven systems moving based on frictional locomotion principles. Symmetrically actuating particles with longitudinal harmonic forces or with longitudinal vibration of the base does not lead to the net motion, unless the generated slip varies during back and forth motion. Harmonically varying the normal contact force and employing asymmetric friction coefficients are two approaches for obtaining frictional locomotion principles. In order to study the simultaneous effect of these required conditions of generating net displacement, a mathematical model is developed, and the resulting non-linear equations of motion are analytically solved. We have shown that the proposed model can be simply generalized to many other frictional, vibration-induced principles, such as the friction drive and the directional friction concepts. The obtained results are in good agreement with those achieved from numerical integration and experiments, reported in the literature. The presented theoretical findings can be effectively used for the design and control of this type of oscillators.

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Yan, Chenkan, Jun Shen, and Peng Lin. "Numerical Investigation on the Strain Evolution of Ti-6Al-4V Alloy during Multi-directional Forging at Elevated Temperatures." High Temperature Materials and Processes 37, no. 6 (June 26, 2018): 571–80. http://dx.doi.org/10.1515/htmp-2016-0223.

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AbstractMulti-directional forging (MDF) is one of the most promising severe plastic deformation (SPD) methods used in fabricating large-scale bulk metal materials with ultra-fine grains (UFG). A finite element model for MDF is developed to investigate the strain evolution of Ti-6Al-4V alloy subjected to MDF. Results show that the billet subjected to MDF can be divided into four individual strain zones in terms of the equivalence of effective strain evolution, and that the strain increment in each individual strain zone varies from pass to pass. The deviation between the maximum and the minimum strain increases with the increase of passes and friction coefficient. The effective strain linearly decreases from the core to the exterior of the billet in all three directions after the MDF process. With the increase of the passes and friction coefficient, the gradient of the effective strain in the billet increases in all three directions due to the difference of deformability in different individual strain zones. For the definite friction coefficient, the average and maximum effective strains are in proportion to the accumulative compression strain.

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15

Rochdi, M., M. Shillor, and M. Sofonea. "A quasistatic contact problem with directional friction and damped response." Applicable Analysis 68, no. 3-4 (April 1998): 409–22. http://dx.doi.org/10.1080/00036819808840639.

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Buttsworth, D. R., S. J. Elston, and T. V. Jones. "Directional sensitivity of skin friction measurements using nematic liquid crystal." Measurement Science and Technology 9, no. 11 (November 1, 1998): 1856–65. http://dx.doi.org/10.1088/0957-0233/9/11/011.

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Lu, Ping, Robert J. K. Wood, Mark G. Gee, Ling Wang, and Wilhelm Pfleging. "The use of anisotropic texturing for control of directional friction." Tribology International 113 (September 2017): 169–81. http://dx.doi.org/10.1016/j.triboint.2017.02.005.

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Yerlikaya, Hakan, and Satsuya Soda. "Experimental and analytical study on sliding vibration of a solid body." Journal of Vibration and Control 25, no. 18 (June 17, 2019): 2480–93. http://dx.doi.org/10.1177/1077546319857631.

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It is accepted that the use of base isolation systems within a structure offers a decreased amount of maximum acceleration value throughout the structure and provides a higher level of comfort and safety to the residents even during extremely strong ground motions. We want to propose a new low-cost structural system with the aforementioned benefits of the base isolation. A structural model was developed using an ultra-high-molecular-weight polyethylene film as a friction surface for the whole concrete base of a residential house, creating a friction-based base-isolation system. To understand the friction behavior between the two materials, a computer model was developed in SAP2000 software, and experiments were conducted to confirm the computer model’s proposed behavior. The created computer model is capable of accounting for the adjustments of the dynamic and static friction parameters depending on the velocity of the block. It is possible to conduct the numerical analysis with three-directional input to the system as well as nonlinear solving capabilities. The results of the numerical analysis are compared with the experiment results on a one-directional wave, along with the 1995 Kobe Earthquake ground motion record that had an input in three directions. The results confirm the reproducibility and predictable behavior of the proposed base-isolation method. The maximum acceleration of the concrete base will be no greater than nearly 30% of gravity acceleration regardless of the maximum acceleration of the ground motion.

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Abe, Koyu, Yusuke Tanida, and Masaru Uchiyama. "Structural Analysis of Directional Deflection Beams." Journal of Robotics and Mechatronics 17, no. 3 (June 20, 2005): 359–66. http://dx.doi.org/10.20965/jrm.2005.p0359.

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Parallel leaf springs are often used for precise linear motion because of their simplicity and freedom from static friction in cases where elasticity and high deformation are required. Using a parallel beam in force sensing requires minimum deflection and limited stress concentration. We previously proposed a unidirectional force sensor based on the H-slit parallel beam structure – an extension of conventional parallel beam. In this paper, we use finite element analysis (FEA) to investigate parallel beam structures that deflect easily in one direction, and evaluate the optimum profile for the notch in the H-slit beam and applications of the parallel beam structure.

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Wang, Qing Ming, and Jia Chen Ju. "Analysis of the Effect of External Factors to the Propulsion by Inertial Centrifugal Force of Rotating Mechanism." Applied Mechanics and Materials 487 (January 2014): 343–47. http://dx.doi.org/10.4028/www.scientific.net/amm.487.343.

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The idea of inertial propulsion using rotating parts is always attractive, but great controversy also exists. Some researchers even completely negate this idea in principle, they think it would never be possible to create directional movement by the inertial force. Theory and experimental results show that, in certain conditions, directional movement can be realized by the internal inertia force of the device. In this paper, the influence of the friction condition between the propulsion devices which using rotating eccentric mass to generate inertia force and the external supporting surface on the effect of propulsion has been analyzed. The results show that, when there is friction between the device and the supporting surface, the rotary of eccentric mass in the device will allow the device to produce motion in a given direction; if the parameters of propulsion device (eccentric mass and eccentricity) and the rotary speed of the eccentric mass are given, the friction condition between the device and the support surface will affect the characteristics of directional motion.

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Troyanovskaya, Irina, A. Zhakov, O. Grebenshchikova, S. Voinash, and E. Timofeev. "Directional stability of an agricultural tractor." FME Transactions 49, no. 2 (2021): 456–62. http://dx.doi.org/10.5937/fme2102456t.

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The discrepancy between the plow width and the tractor width leads to the asymmetry of plowing units. The geometry of the plowshare surface of the moldboard plow contributes to the generation of lateral forces on the working tool. All this leads to the imbalance of the tool and the deviation of the tractor from straight-line movement during plowing. To maintain straight-line movement, the driver has to adjust the machine every 5-10 meters, which is highly tiresome. To study the causes of lateral slips of the plowing unit, we constructed a mathematical model, which consists of the equations of controlled movement and equations of the tractor's uncontrolled shear under the action of external forces from the plow. The description of the force interaction of the drive with the ground is based on the mathematical theory of friction, taking into account anisotropy and elastic properties in contact. Based on the passive shear model, we constructed a hodograph diagram of the maximum tractor shear force from the side of the working tool. We found that the shear force reaches its maximum friction value only in the case of a translational shear, when its line of action passes through the tractor's center of gravity. In all other cases, the shift (slip) of the tractor is caused by a lower force. We formulated the features and assumptions of the model as applied to caterpillar and wheeled tractors. As a result, we found that, regardless of the direction of the lateral displacement of the plow's traction resistance, the tractor is slipped towards the plowed field. The result of the numerical experiment showed that the main reason for the slip of the wheeled plowing unit is the difference in soils along the sides of the tractor but not the deviation of the plow traction resistance.

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Liu, Yu, Xi Chen, and Kai Tang. "Research on the Charged Omni-Directional Spatial Electric Field Tester." Advanced Materials Research 681 (April 2013): 110–14. http://dx.doi.org/10.4028/www.scientific.net/amr.681.110.

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The spatial electric field tester is mainly used for the measurement of high-altitude electrostatic field. The spatial electric field tester will be electrostatically charged during the period it is sent to a certain height by a micro-rocket. In order to study the charge characteristics, the paper analyzes the charging mechanism of the omni-directional spatial electric field tester and builds mathematics model for the friction charging, which is a main factor of the charging process. The numerical calculation and experimental research demonstrate that the friction introduces a slow charge accumulation process for the electric field instrument in the course of its campaign. Under the testing conditions in this paper, the charge amount is 10-11 C within the 6s duration. In order to improve the accuracy of the electric field measurement, a time-frequency analysis method can be adopted to remove the slow-varying electric field signal.

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Wan, Ai Lan, and Wei Dong Yu. "Evaluation of The Wool Fiber Surface Modified by Chlorine and Pilling Propensity of Single Jersey." Advanced Materials Research 194-196 (February 2011): 2380–83. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.2380.

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The properties of wool fibers treated with chlorine (Basolan® 88 and Kroy-resin) were compared with surface modification observed by scanning electron microscopy (SEM), frictional properties and mechanical properties. The changes in surface morphology, frictional and physical properties of the single wool fibers are presented. Coating resin on the chlorinated wool fibers results in a significant reduction in the fiber coefficient of friction[1], as the resin smoothes the protruding edges of the fiber scales. However it increases the directional friction effect (DFE) of the fibers. It is postulated that the DFE may limit the ability of those surface fibers to form fuzz and hairiness of spun yarn could reach the critical height required for pill formation. Meanwhile, the fiber tensile strength may be attributed to pills pulling-off during pills formation, indicating a slowing rate of fuzz formation and consequently pill formation.

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Jiang, Wei, Cui Cui Ji, Dan Dan Zhang, Hua Xing Xiao, and Yun Tian Dai. "Fractal Characterization of Relative Movement Modes in Simulated Friction and Wear Tests." Materials Science Forum 944 (January 2019): 426–31. http://dx.doi.org/10.4028/www.scientific.net/msf.944.426.

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The selection of the relative movement mode between the friction pairs in simulated friction and wear tests is a crucial factor for the characterization and evaluation of metallic material properties. In this study, two kinds of commonly used metal materials (stainless steel 0Cr18Ni9 and aluminum alloy 2A12) were applied for the simulated friction and wear tests with four different modes of relative motion, including unidirectional, reciprocating, circular and multi-directional cross-shear. The corresponding surface topography and statistical parameters such as surface roughness Ra were obtained via OLYMPUS ultra-depth microscope. Based on the fractal theory, fractal dimension D was calculated to characterize the surface topography and the results indicate that, the fractal dimension D of the unidirectional and multi-directional cross-shear simulated friction and wear tests is the minimum and maximum respectively, which reflects that the fractal dimension D is able to characterize the complexity of the surface morphology. The fractal dimension D may be related to the intrinsic physical properties of metal materials, such as hardness and toughness, which needs to be further studied.

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Oliveto, Nicholas D. "Geometrically nonlinear analysis of friction pendulum systems under tri-directional excitation." Engineering Structures 269 (October 2022): 114770. http://dx.doi.org/10.1016/j.engstruct.2022.114770.

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Gidoni, Paolo, and Antonio DeSimone. "On the genesis of directional friction through bristle-like mediating elements." ESAIM: Control, Optimisation and Calculus of Variations 23, no. 3 (May 3, 2017): 1023–46. http://dx.doi.org/10.1051/cocv/2017030.

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Bakre, S. V., R. S. Jangid, and G. R. Reddy. "Response of piping system on friction support to bi-directional excitation." Nuclear Engineering and Design 237, no. 2 (January 2007): 124–36. http://dx.doi.org/10.1016/j.nucengdes.2005.12.012.

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Sugiura, Takanori, Masamichi SAKAGUCHI, and Hideo FUJIMOTO. "1P1-D08 Study on Directional Control Using Rotor Friction Haptic Interface." Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) 2006 (2006): _1P1—D08_1—_1P1—D08_2. http://dx.doi.org/10.1299/jsmermd.2006._1p1-d08_1.

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Okabe, S., Y. Yokoyama, and G. Boothroyd. "Analysis of vibratory feeding where the track has directional friction characteristics." International Journal of Advanced Manufacturing Technology 3, no. 4 (August 1988): 73–85. http://dx.doi.org/10.1007/bf02601835.

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Maidla, Eric E., and Andrew K. Wojtanowicz. "A field method for assessing borehole friction for directional well casing." Journal of Petroleum Science and Engineering 1, no. 4 (October 1988): 323–33. http://dx.doi.org/10.1016/0920-4105(88)90007-1.

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He, Jiang Fu, He Liu, Kun Yin, and Xin Gan. "Field Tests on the Application of Oscillation Tool with a Fluidic Amplifier to Directional Well Drilling." Applied Mechanics and Materials 741 (March 2015): 599–602. http://dx.doi.org/10.4028/www.scientific.net/amm.741.599.

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The directional well drilling technology is extensively utilized and developed throughout the world. However, series of drilling problems occurred in the operation process of directional drilling. In order to reduce the friction of drilling tools, an oscillation tool with a fluidic amplifier has been field tested, and the pressure pulse of oscillation tool has been obtained. Field test results have shown that the oscillation tool has an extensive flexibility to directional well drilling, and the oscillation tool could stably actuate the drilling tool to have reciprocating vibration, which contributes to the friction and drag reduction of drilling tools. Furthermore, it can be concluded that the pressure pulse value generated by pumped fluid varies with input flow rate, and the pressure of oscillation tool increases while the flow rate is increasing. In addition, the motion frequency of the oscillation tool is exponentially increasing with the raise of pumped flow rate.

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Tong, Hua, and Yongbo Shao. "Mechanical Analysis of DS in Horizontal Directional Drilling." Applied Sciences 12, no. 6 (March 19, 2022): 3145. http://dx.doi.org/10.3390/app12063145.

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In recent years, trenchless horizontal directional drilling (HDD) technology has developed rapidly towards the direction of large pipe diameter and long span. During construction, the buckling deformation and large drag torque of the drillstring (DS) are the key problems restricting the development of the HDD technology. In order to understand the buckling deformation law of the DS in horizontal directional drilling engineering, as well as the transfer and the distribution of the drag torque, and the relationship between the buckling deformation and drag torque, the dynamic model of the DS system in drilling engineering is applied to HDD engineering. The dynamics model of HDD at a long distance (5200 m) is established and calculated. The research indicates (1) when the buckling deformation of the DS is small, priority should be given to reducing the friction and torsion at the bending position; (2) excessive inlet thrust is the main reason for the buckling deformation of the DS, and the smaller the hole diameter, the more serious the buckling deformation; (3) severe buckling deformation of the DS will lead to an increase in the frictional resistance at the deformed part, and even local self-locking, resulting in the inability to continue to increase the weight on bit (WOB). The research results preliminarily reveal the relationship between DS buckling deformation and drag torque in ultra-long distance HDD engineering and point out the phenomenon law of drag torque and buckling deformation, which has reference value for the development of HDD technology.

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Zhang, Xu, Jia-Hui Cao, Bao-Quan Ai, Tian-Fu Gao, and Zhi-Gang Zheng. "Investigation on the directional transportation of coupled Brownian motors with asymmetric friction." Acta Physica Sinica 69, no. 10 (2020): 100503. http://dx.doi.org/10.7498/aps.69.20191961.

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Jangid, R. S. "Response of pure-friction sliding structures to bi-directional harmonic ground motion." Engineering Structures 19, no. 2 (February 1997): 97–104. http://dx.doi.org/10.1016/s0141-0296(96)00055-7.

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Chen, Huazhi, Shengyuan Jiang, Rongkai Liu, and Weiwei Zhang. "Particle Directional Conveyance under Longitudinal Vibration by considering the Trough Surface Texture: Numerical Simulation Based on the Discrete Element Method." Shock and Vibration 2018 (2018): 1–13. http://dx.doi.org/10.1155/2018/8260462.

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Particles can move directionally in a trough with finlike asperities under longitudinal vibrations. Here, we present an analysis of the particle conveyance mechanism and the influence of the asperity shape on the particle conveyance capacity by employing a numerical simulation based on the discrete element method (DEM). A dynamic-static matching method is proposed to characterize the three microcontact parameters in the simulation: the restitution coefficient, static friction coefficient, and rolling friction coefficient. The simulation shows that the asymmetric force induced by the finlike asperities and its cumulative effect over time lead to the particle directional conveyance. The conveyance velocity increases with increasing vibration time and is related to the median coordination number. The asperity height and slope inclination angles determine the trough shape and distance between two asperities directly. An undersized or oversized distance reduces the steady conveyance velocity. We find the optimal distance to be between one and two particle diameters.

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Xing, Jichun, Huajun Li, and Dechun Liu. "Anisotropic Vibration Tactile Model and Human Factor Analysis for a Piezoelectric Tactile Feedback Device." Micromachines 10, no. 7 (July 3, 2019): 448. http://dx.doi.org/10.3390/mi10070448.

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Tactile feedback technology has important development prospects in interactive technology. In order to enrich the tactile sense of haptic devices under simple control, a piezoelectric haptic feedback device is proposed. The piezoelectric tactile feedback device can realize tactile changes in different excitation voltage amplitudes, different excitation frequencies, and different directions through the ciliary body structure. The principle of the anisotropic vibration of the ciliary body structure was analyzed here, and a tactile model was established. The equivalent friction coefficient under full-coverage and local-coverage of the skin of the touch beam was deduced and solved. The effect of system parameters on the friction coefficient was analyzed. The results showed that in the full-coverage, the tactile effect is mainly affected by the proportion of the same directional ciliary bodies and the excitation frequency. The larger the proportion of the same direction ciliary body is, the smaller the coefficient of friction is. The larger the excitation frequency is, the greater the coefficient of friction is. In the local-coverage, the tactile effect is mainly affected by the touch position and voltage amplitude. When changing the touch pressure, it has a certain effect on the change of touch, but it is relatively weak. The experiment on the sliding friction of a cantilever touch beam and the experiment of human factor were conducted. The experimental results of the sliding friction experiment are basically consistent with the theoretical calculations. In the human factor experiment, the effects of haptic regulation are mainly affected by voltage or structure of the ciliary bodies.

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Mitchell, Jeffrey P., Bum-Yean Cho, and Yoo-Jae Kim. "Analytical Model of Two-Directional Cracking Shear-Friction Membrane for Finite Element Analysis of Reinforced Concrete." Materials 14, no. 6 (March 17, 2021): 1460. http://dx.doi.org/10.3390/ma14061460.

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There are a multitude of existing material models for the finite element analysis of cracked reinforced concrete that provide reduced shear stiffness but do not limit shear strength. In addition, typical models are not based on the actual physical behavior of shear transfer across cracks by shear friction recognized in the ACI 318 Building Code. A shear-friction model was recently proposed that was able to capture the recognized cracked concrete behavior by limiting shear strength as a yielding function in the reinforcement across the crack. However, the proposed model was formulated only for the specific case of one-directional cracking parallel to the applied shear force. This study proposed and generalized an orthogonal-cracking shear-friction model for finite element use. This was necessary for handling the analysis of complex structures and nonproportional loading cases present in real design and testing situations. This generalized model was formulated as a total strain-based model using the approximation that crack strains are equal to total strains, using the proportional load vector, constant vertical load, and modified Newton–Raphson method to improve the model’s overall accuracy.

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Zhang, Z. M., Q. An, W. J. Zhang, Q. Yang, Y. J. Tang, and X. B. Chen. "Modeling of directional friction on a fully lubricated surface with regular anisotropic asperities." Meccanica 46, no. 3 (June 9, 2010): 535–45. http://dx.doi.org/10.1007/s11012-010-9303-2.

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39

Xi-ying, Shen, and Gao Da-zhao. "Effect of skin friction on the directional stability of driven piles during driving." Applied Mathematics and Mechanics 13, no. 12 (December 1992): 1143–48. http://dx.doi.org/10.1007/bf02456155.

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40

Plamadeala, C., F. Hischen, R. Friesenecker, R. Wollhofen, J. Jacak, G. Buchberger, E. Heiss, T. A. Klar, W. Baumgartner, and J. Heitz. "Bioinspired polymer microstructures for directional transport of oily liquids." Royal Society Open Science 4, no. 3 (March 2017): 160849. http://dx.doi.org/10.1098/rsos.160849.

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Nature has always served as an inspiration for scientists, helping them to solve a large diversity of technical problems. In our case, we are interested in the directional transport of oily liquids and as a model for this application we used the flat bug Dysodius lunatus . In this report, we present arrays of drops looking like polymer microstructures produced by the two-photon polymerization technique that mimic the micro-ornamentation from the bug's cuticle. A good directionality of oil transport was achieved, directly controlled by the direction of the pointed microstructures at the surface. If the tips of the drop-like microstructures are pointing towards the left side, the liquid front moves to the right and vice versa. Similar effects could be expected for the transport of oily lubricants. These results could, therefore, be interesting for applications in friction and wear reduction.

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Dong, Shi Min, and Ming Ming Xing. "Simulating Sliding Efficiency of Belt Driving Acted on by Bi-Directional Alternating Load." Advanced Materials Research 308-310 (August 2011): 1900–1909. http://dx.doi.org/10.4028/www.scientific.net/amr.308-310.1900.

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With the belt driving device which is affected by bi-directional alternating load taken as research object and with the elastic slide between belt and pulley which is caused by elastic deformation of the belt considered, the calculating model of belt instantaneous sliding friction is established. The belt is simplified to elastic body of longitudinal vibration, the mechanical model of the belt longitudinal vibration which is excited by alternating friction is established, and the mathematical model of the wave equation form is established. The numerical simulation model of wave equation is carried out on using the superposition method of mode of vibration. The simulation models of the belt instantaneous sliding velocity and the belt instantaneous sliding efficiency are presented. The factors affecting sliding efficiency are pointed out, such as oscillation amplitude of alternating torque and initial tension of belt. The following conclusions are obtained by the simulating results: (1) load torque fluctuations will lead to lower sliding efficiency; (2) specifically, the sliding efficiency will decrease obviously in the area where the direction of load torque is occurring; (3) on condition that the belt doesn’t skid, the sliding efficiency of the belt reduces with the increase of initial tension, and the sliding efficiency will increase through optimizing the initial tension of belt.

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Paswan, Ramashankar, Jayanta Das, N. Kumar, Ajit Kumar, Santosh Kumar Mishra, and Kumar Sujit. "Performance Analysis of Directional Control Valve: An Overview." Applied Mechanics and Materials 592-594 (July 2014): 1983–87. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.1983.

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Directional control valves start, stop or change the direction of flow in compressed air applications. To understand the different applications of compressed air and how valves are used, one must first have knowledge of the kinds and types of valves used by industries. This paper studies local valve control of the electro-hydraulic system. The slow response of hydraulic control valve usually becomes the hold-up of whole system performance. Although fast valves (e.g. high-bandwidth servo-valves) are available, they are far more expensive than slow valves (e.g. proportional directional control valves). To improve the performance of proportional directional control valves, three different types of controllers are synthesized. Firstly, based on the pole zero cancellation technique, an open loop compensator is designed which requires the accurate valve dynamic model information; Secondly, a full state feedback adaptive robust controller (ARC) is synthesized, which effectively takes into account the effect of parametric uncertainties and uncertain nonlinearities such as friction force and flow force. Finally, an output feedback ARC controller is synthesized to address the problem of un measurable states. Keywords: valve, hydraulic device, Simulink.

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Madsen, Ole Secher, Ying-Keung Poon, and Hans C. Graber. "SPECTRAL WAVE ATTENUATION BY BOTTOM FRICTION: THEORY." Coastal Engineering Proceedings 1, no. 21 (January 29, 1988): 34. http://dx.doi.org/10.9753/icce.v21.34.

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Based on the linearized form of the boundary layer equations and a simple eddy viscosity formulation of shear stress, the turbulent bottom boundary layer flow is obtained for a wave motion specified by its directional spectrum. Closure is obtained by requiring the solution to reduce, in the limit, to that of a simple harmonic wave. The resulting dissipation is obtained in spectral form with a single friction factor determined from knowledge of the bottom roughness and an equivalent monochromatic wave having the same root-mean-square near-bottom orbital velocity and excursion amplitude as the specified wave spectrum. The total spectral dissipation rate is obtained by integration and compared with the average dissipation obtained from a model considering the statistics of individual waves defined by their maximum orbital velocity and zero-crossing period. The agreement between the two different evaluations of total spectral dissipation supports the validity of the spectral dissipation model.

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44

Zuo, Qiang, Jialei Sun, Qianqian Lu, and Jian Ruan. "Experimental and numerical investigations of the ball-screw-type coupling in two-dimensional electro-hydraulic proportional directional valve." Advances in Mechanical Engineering 10, no. 9 (September 2018): 168781401880250. http://dx.doi.org/10.1177/1687814018802509.

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To realize rotary and linear motions of a single spool for improving a proportional displacement of the spool, a new structure of ball screw compression–torsion coupling is proposed, which is used in the two-dimensional electro-hydraulic proportional directional valve. Its principal is based on changing the spiral angle of the raceway to magnify the thrust of a wet proportional electromagnet and realize the rotary to linear motion of a single spool. In addition, because of the rolling friction instead of the sliding friction, the friction resistance is reduced. The mathematical model of the valve is established and the characteristics of the valve are simulated and analyzed by MATLAB. Theoretical and experimental results show that the no-load hysteresis of the ball screw compression–torsion coupling is up to 1% under the flutter compensation. At the system pressure of 21 MPa, the flow hysteresis of the valve is less than 5%, and the nonlinear degrees of the input displacement of electromagnet and the output displacement of the valve core are both less than 1%. The width of the valve corresponding to −3 dB and −90° is about 12 Hz, and the step response time of the valve is about 0.45 s without overshoot.

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Kilikevičius, Sigitas, Algimantas Fedaravičius, Virginija Daukantienė, Kristina Liutkauskienė, and Linas Paukštaitis. "Manipulation of Miniature and Microminiature Bodies on a Harmonically Oscillating Platform by Controlling Dry Friction." Micromachines 12, no. 9 (September 9, 2021): 1087. http://dx.doi.org/10.3390/mi12091087.

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Currently used nonprehensile manipulation systems that are based on vibrational techniques employ temporal (vibrational) asymmetry, spatial asymmetry, or force asymmetry to provide and control a directional motion of a body. This paper presents a novel method of nonprehensile manipulation of miniature and microminiature bodies on a harmonically oscillating platform by creating a frictional asymmetry through dynamic dry friction control. To theoretically verify the feasibility of the method and to determine the control parameters that define the motion characteristics, a mathematical model was developed, and modeling was carried out. Experimental setups for miniature and microminiature bodies were developed for nonprehensile manipulation by dry friction control, and manipulation experiments were carried out to experimentally verify the feasibility of the proposed method and theoretical findings. By revealing how characteristic control parameters influence the direction and velocity, the modeling results theoretically verified the feasibility of the proposed method. The experimental investigation verified that the proposed method is technically feasible and can be applied in practice, as well as confirmed the theoretical findings that the velocity and direction of the body can be controlled by changing the parameters of the function for dynamic dry friction control. The presented research enriches the classical theories of manipulation methods on vibrating plates and platforms, as well as the presented results, are relevant for industries dealing with feeding, assembling, or manipulation of miniature and microminiature bodies.

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Okamura, Toshikazu. "Effect of Directional Surface Finish of Brake Discs on Friction Behavior During Running-in." SAE International Journal of Passenger Cars - Mechanical Systems 4, no. 3 (September 18, 2011): 1445–52. http://dx.doi.org/10.4271/2011-01-2382.

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47

Jain, Vipin, Wei Yuan, R. S. Mishra, Gouthama, and Anil K. Gupta. "Directional Anisotropy in the Mechanical Behavior of Friction Stir Processed and Aged AZ91 Alloy." Materials Science Forum 702-703 (December 2011): 64–67. http://dx.doi.org/10.4028/www.scientific.net/msf.702-703.64.

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Friction stir processing (FSP) is an emerging grain refinement technique for magnesium alloys. In this study, a cast AZ91 alloy was processed by a single-pass FSP to achieve an average grain size of ~6 mm in the nugget zone. The FSP is found to introduce texture in the alloy due to preferred alignment of basal poles in the processing direction. The mechanical behavior is significantly influenced by texture. After FSP, the alloy was aged at different temperatures and times for continuous and discontinuous precipitation of b-Mg17Al12. A high anisotropy in yield stress is observed in the processing and transverse direction after FSP. It is shown that this anisotropy can be minimized under optimum ageing conditions. The observed yield asymmetry is correlated with the texture variation after FSP. The role of b-Mg17Al12 precipitates in reducing the yield anisotropy is also discussed.

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Jin, Liyang, and Qingfeng Wang. "Positioning control of hydraulic cylinder with unknown friction using on/off directional control valve." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 232, no. 8 (May 11, 2018): 983–93. http://dx.doi.org/10.1177/0959651818771522.

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In this study, a prediction-based positioning control scheme is proposed for the hydraulic cylinder controlled by a solenoid operated on/off directional control valve. The discrete-valued input, low switching frequency and significant delay of directional control valve make the control problem very complex. Only a discrete-valued control input can be used here; meanwhile, the input has switching frequency constraint and time-delay. Existing methods such as pulse-width modulation control and sliding-mode control are not suitable for this problem, because chattering may arise due to the control input restrictions. The newly proposed prediction-based positioning control scheme consists of two parts: a switching law based on predictions of future states and learning algorithms which learn required predictive models online. According to accurate predictions, the switching law can control the hydraulic cylinder to target position in an optimal way, and chattering is avoided. Meanwhile, the required predictive models are identified by a generalized growing and pruning for radial basis function network and a recursive least square estimation algorithm in real time. Essentially, the problems caused by input restrictions, time-delay and model uncertainty are solved by the accurate identifications to some well-designed models. The control scheme is verified by physical experiments. Fast and accurate positioning control can be achieved for the hydraulic cylinder with unknown nonlinear friction.

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Resendiz, Jesus, Eldon Graham, Philip Egberts, and Simon S. Park. "Directional friction surfaces through asymmetrically shaped dimpled surfaces patterned using inclined flat end milling." Tribology International 91 (November 2015): 67–73. http://dx.doi.org/10.1016/j.triboint.2015.06.025.

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Guo, W., L. Chu, L. Yang, and T. F. Fwa. "Determination of tire rubber-pavement directional coefficient of friction based on contact mechanism considerations." Tribology International 179 (January 2023): 108178. http://dx.doi.org/10.1016/j.triboint.2022.108178.

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Journal articles on the topic 'Directional friction'

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