Influence of the Degree of Inclination of Applied Load on the Behaviour of Hybrid and FRP Elements

2021 ◽  
pp. 1020-1030
Author(s):  
Ausra Vadapolaite ◽  
Mohammad Dakhel ◽  
Ted Donchev
Keyword(s):  

The work of multilayer glass structures for central and eccentric compression and bending are considered. The substantiation of the chosen research topic is made. The description and features of laminated glass for the structures investigated, their characteristics are presented. The analysis of the results obtained when testing for compression, compression with bending, simple bending of models of columns, beams, samples of laminated glass was made. Overview of the types and nature of destruction of the models are presented, diagrams of material operation are constructed, average values of the resistance of the cross-sections of samples are obtained, the table of destructive loads is generated. The need for development of a set of rules and guidelines for the design of glass structures, including laminated glass, for bearing elements, as well as standards for testing, rules for assessing the strength, stiffness, crack resistance and methods for determining the strength of control samples is emphasized. It is established that the strength properties of glass depend on the type of applied load and vary widely, and significantly lower than the corresponding normative values of the strength of heat-strengthened glass. The effect of the connecting polymeric material and manufacturing technology of laminated glass on the strength of the structure is also shown. The experimental values of the elastic modulus are different in different directions of the cross section and in the direction perpendicular to the glass layers are two times less than along the glass layers.


Proceedings ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 2
Author(s):  
Arash M. Shahidi ◽  
Theodore Hughes-Riley ◽  
Carlos Oliveira ◽  
Tilak Dias

Knitted electrodes are a key component to many electronic textiles including sensing devices, such as pressure sensors and heart rate monitors; therefore, it is essential to assess the electrical performance of these knitted electrodes under different mechanical loads to understand their performance during use. The electrical properties of the electrodes could change while deforming, due to an applied load, which could occur in the uniaxial direction (while stretched) or multiaxial direction (while compressed). The properties and performance of the electrodes could also change over time when rubbed against another surface due to the frictional force and generated heat. This work investigates the behavior of a knitted electrode under different loading conditions and after multiple abrasion cycles.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4217
Author(s):  
Üsame Ali Usca ◽  
Mahir Uzun ◽  
Mustafa Kuntoğlu ◽  
Serhat Şap ◽  
Khaled Giasin ◽  
...  

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.


Author(s):  
G Girish ◽  
V Anandakrishnan

In this work, an Al–Zn–Mg–Cu/TiC metal–matrix composite was fabricated through recursive friction stir processing, and its microstructure, hardness, and tribological properties were investigated. Microstructure examination revealed a homogeneous dispersion of TiC particles in the matrix after six recursive passes. The grains were significantly refined and microhardness of the composite improved due to the presence of TiC particles. Friction coefficient and wear rate of the composite went up with an increase in the applied load and dropped significantly at higher sliding velocities. The morphology of the wear specimens experimented under different testing conditions was analyzed and the corresponding wear mechanisms discussed.


Friction ◽  
2021 ◽  
Author(s):  
Thi D. Ta ◽  
Hien D. Ta ◽  
Kiet A. Tieu ◽  
Bach H. Tran

AbstractThe rapid development of molecular dynamics (MD) simulations, as well as classical and reactive atomic potentials, has enabled tribologists to gain new insights into lubrication performance at the fundamental level. However, the impact of adopted potentials on the rheological properties and tribological performance of hydrocarbons has not been researched adequately. This extensive study analyzed the effects of surface structure, applied load, and force field (FF) on the thin film lubrication of hexadecane. The lubricant film became more solid-like as the applied load increased. In particular, with increasing applied load, there was an increase in the velocity slip, shear viscosity, and friction. The degree of ordering structure also changed with the applied load but rather insignificantly. It was also significantly dependent on the surface structure. The chosen FFs significantly influenced the lubrication performance, rheological properties, and molecular structure. The adaptive intermolecular reactive empirical bond order (AIREBO) potential resulted in more significant liquid-like behaviors, and the smallest velocity slip, degree of ordering structure, and shear stress were compared using the optimized potential for liquid simulations of united atoms (OPLS-UAs), condensed-phase optimized molecular potential for atomic simulation studies (COMPASS), and ReaxFF. Generally, classical potentials, such as OPLS-UA and COMPASS, exhibit more solid-like behavior than reactive potentials do. Furthermore, owing to the solid-like behavior, the lubricant temperatures obtained from OPLS-UA and COMPASS were much lower than those obtained from AIREBO and ReaxFF. The increase in shear stress, as well as the decrease in velocity slip with an increase in the surface potential parameter ζ, remained conserved for all chosen FFs, thus indicating that the proposed surface potential parameter ζ for the COMPASS FF can be verified for a wide range of atomic models.


Author(s):  
Raj Kumar Singh ◽  
Amit Telang ◽  
Satyabrata Das

Abstract The effects of friction heat and friction coefficient on the abrasive wear response of Al-7.5Si–SiCp composite against low-cost hypereutectic (Al-17.5Si) alloy were investigated as functions of the abrasive size and applied load in both as-cast and after heat-treatment conditions. Experiments were performed on pin-on-disc apparatus at 38 –80 μm abrasive size, 5 – 20 N applied load, 100 –400 m abrading (sliding) distances and 1 m s–1 constant sliding speed. The frictional heating of as-cast and heat-treated composite was superior compared to the matrix alloy and hypereutectic alloy, whereas the trend reversed for the friction coefficient. The frictional heating and friction coefficient of the materials increased with the abrasive size and applied load in both as-cast and after heat-treatment. The worn surface and wear debris particles were examined by using field emission scanning electron microscopy to understand the wear mechanism.


2001 ◽  
Vol 33 (10) ◽  
pp. 1713-1725 ◽  
Author(s):  
JAMES W. MATHESON ◽  
THOMAS W. KERNOZEK ◽  
DENNIS C. W. FATER ◽  
GEORGE J. DAVIES

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1550 ◽  
Author(s):  
Yunhai Liu ◽  
Lei Chen ◽  
Bin Zhang ◽  
Zhongyue Cao ◽  
Pengfei Shi ◽  
...  

The friction of hydrogenated diamond-like carbon (H-DLC) films was evaluated under the controlled environments of humid air and vacuum by varying the applied load. In humid air, there is a threshold applied load below which no obvious friction drop occurs and above which the friction decreases to a relatively low level following the running-in process. By contrast, superlubricity can be realized at low applied loads but easily fails at high applied loads under vacuum conditions. Further analysis indicates that the graphitization of the sliding H-DLC surface has a negligible contribution to the sharp drop of friction during the running-in process under both humid air and vacuum conditions. The low friction in humid air and the superlow friction in vacuum are mainly attributed to the formation and stability of the transfer layer on the counterface, which depend on the load and surrounding environment. These results can help us understand the low-friction mechanism of H-DLC film and define optimized working conditions in practical applications, in which the transfer layer can be maintained for a long time under low applied load conditions in vacuum, whereas a high load can benefit the formation of the transfer layer in humid air.


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