scholarly journals Optimization of friction parameters in the process of wood welding without additional adhesives

2016 ◽  
pp. 0501-0507
Author(s):  
Izet Horman ◽  
Ibrahim Busuladzic ◽  
Ismar Hajro ◽  
Ninoslav Beljak
Keyword(s):  
Friction Parameters

Tribotechnical characteristics of hard alloys in sliding friction units

2020 ◽  
pp. 87-97
Author(s):  
K. D. Khromushkin ◽  
B. G. Ushakov ◽  
A. V. Kochergin ◽  
R. A. Suleev ◽  
O. N. Parmenova
Keyword(s):  
Experimental Data ◽  
Sliding Friction ◽  
Heating Temperature ◽  
Hard Alloys ◽  
Friction Units ◽  
Wear And Friction ◽  
Friction Path ◽  
Friction Parameters ◽  
Tribotechnical Characteristics ◽  
Temperature Surface

The paper presents experimental data on the study of the friction parameters of hard alloys in sliding friction units, including the heating temperature, surface roughness, wear and friction coefficient, depending on the duration of the test and the friction path.

scholarly journals Asymmetric and chaotic responses of dry friction oscillators with different static and kinetic coefficients of friction

Meccanica ◽  
2021 ◽  
Author(s):  
Gábor Csernák ◽  
Gábor Licskó
Keyword(s):  
Dry Friction ◽  
Continuation Method ◽  
Friction Model ◽  
Lugre Friction Model ◽  
Kinetic Coefficients ◽  
Friction Oscillator ◽  
Lugre Friction ◽  
Friction Parameters ◽  
Two Parameter ◽  
Parameter Bifurcation

AbstractThe responses of a simple harmonically excited dry friction oscillator are analysed in the case when the coefficients of static and kinetic coefficients of friction are different. One- and two-parameter bifurcation curves are determined at suitable parameters by continuation method and the largest Lyapunov exponents of the obtained solutions are estimated. It is shown that chaotic solutions can occur in broad parameter domains—even at realistic friction parameters—that are tightly enclosed by well-defined two-parameter bifurcation curves. The performed analysis also reveals that chaotic trajectories are bifurcating from special asymmetric solutions. To check the robustness of the qualitative results, characteristic bifurcation branches of two slightly modified oscillators are also determined: one with a higher harmonic in the excitation, and another one where Coulomb friction is exchanged by a corresponding LuGre friction model. The qualitative agreement of the diagrams supports the validity of the results.

scholarly journals Ultrasonic Characterization of Nanoparticle-Based Ceramics Fabricated by Spark-Plasma Sintering

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 135-147
Author(s):  
Hanuš Seiner ◽  
Michaela Janovská ◽  
Martin Koller ◽  
Petr Sedlák ◽  
Kateřina Seinerová ◽  
...  
Keyword(s):  
Activation Energy ◽  
Boron Nitride ◽  
Internal Friction ◽  
Elastic Constants ◽  
Carbon Nitride ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Friction Parameters ◽  
Boron Carbon Nitride ◽  
Boron Carbon

Resonant ultrasound spectroscopy was used to determine elastic constants and internal friction parameters of bulk nanoparticle-based ceramic materials compacted by spark plasma sintering. Boron nitride-based and boron carbon nitride-based materials were studied, and the results were compared with similar bulk materials prepared from graphene nanoplatelets. The results showed that such nanoparticle-based materials can be strongly anisotropic, and can have very different elastic constants depending on the nanoparticles used. From the temperature dependence of the internal friction parameters, the activation energy for sliding of the individual monolayers along each other was determined for each material. Very similar values of the activation energy were obtained for boron nitride, boron carbon nitride, and graphene, ranging from 15 to 17 kJ/mol.

scholarly journals Sliding Mode Robot Control with Friction and Payload Estimation

2004 ◽  
Vol 8 (5) ◽  
pp. 553-561 ◽  
Author(s):  
Lörinc Márton ◽  
◽  
Béla Lantos ◽  
Keyword(s):  
Robot Control ◽  
Control Algorithm ◽  
Lyapunov Method ◽  
Sliding Mode ◽  
Robot Arm ◽  
Tracking Accuracy ◽  
Parameter Adaptation ◽  
Robust Parameter ◽  
Payload Mass ◽  
Friction Parameters

The paper deals with robust motion control of robotic systems with unknown friction parameters and payload mass. The parameters of the robot arm were considered known with a given precision. To solve the control of the robot with unknown payload mass and friction parameters, sliding mode control algorithm was proposed combined with robust parameter adaptation techniques. Using Lyapunov method it was shown that the resulting controller achieves a guaranteed final tracking accuracy. Simulation results are presented to illustrate the effectiveness and achievable control performance of the proposed scheme.

scholarly journals Fundamentals of Force-Controlled Friction Riveting: Part II—Joint Global Mechanical Performance and Energy Efficiency

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2489 ◽  
Author(s):  
Gonçalo Pina Cipriano ◽  
Lucian Blaga ◽  
Jorge dos Santos ◽  
Pedro Vilaça ◽  
Sergio Amancio-Filho
Keyword(s):  
Energy Efficiency ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Tensile Force ◽  
Optimization Approach ◽  
Additional Energy ◽  
Efficient Manner ◽  
Control Optimization ◽  
Friction Parameters ◽  
And Control

The present work investigates the correlation between energy efficiency and global mechanical performance of hybrid aluminum alloy AA2024 (polyetherimide joints), produced by force-controlled friction riveting. The combinations of parameters followed a central composite design of experiments. Joint formation was correlated with mechanical performance via a volumetric ratio (0.28–0.66 a.u.), with a proposed improvement yielding higher accuracy. Global mechanical performance and ultimate tensile force varied considerably across the range of parameters (1096–9668 N). An energy efficiency threshold was established at 90 J, until which, energy input displayed good linear correlations with volumetric ratio and mechanical performance (R-sq of 0.87 and 0.86, respectively). Additional energy did not significantly contribute toward increasing mechanical performance. Friction parameters (i.e., force and time) displayed the most significant contributions to mechanical performance (32.0% and 21.4%, respectively), given their effects on heat development. For the investigated ranges, forging parameters did not have a significant contribution. A correlation between friction parameters was established to maximize mechanical response while minimizing energy usage. The knowledge from Parts I and II of this investigation allows the production of friction riveted connections in an energy efficient manner and control optimization approach, introduced for the first time in friction riveting.

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