Article
Engineering, Aerospace
Heidi D. Beemer, Ian R. McNab
Summary: This paper presents a solution for obtaining propellent for future space missions by utilizing an electromagnetic launcher (EML) to transport raw materials from the lunar south pole to NASA's Lunar Gateway. The study demonstrates the feasibility of a single launch from the lunar south pole to intercept any point along the Gateway's orbit. The successful sourcing of lunar hydrogen to the Gateway would greatly benefit NASA's Artemis program and the exploration of the solar system.
Article
Chemistry, Physical
Haojie Lang, Yimeng Xu, Pengzhe Zhu, Yitian Peng, Kun Zou, Kang Yu, Yao Huang
Summary: Graphene as a solid lubricant at electrical contact interfaces exhibits ultra-low friction, ultra-high current stability, and effective wear resistance.
Article
Engineering, Mechanical
Guiwen Liao, Wei Wang, Chunjie Wei, Huan Zhao, Xiaojun Liu
Summary: This study investigates the armature/rail (A/R) interface under high-intensity currents and transient high-temperature conditions using the magneto-thermo-hydrodynamic lubrication theory. A coupling model is established to describe the lubrication mechanism and analyze the dynamic lubrication properties of the metal liquid film at the interface. The findings are important for enhancing the stability and performance of electromagnetic rail launch.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Carlos Gabriel Figueroa, Rafael Schouwenaars, Roumen Petrov, Leo Kestens
Summary: This work investigates the impact of annealing conditions on tribolayer formation in copper under dry sliding conditions. It is found that annealing time leads to an increase in grain size, decrease in hardness, and increase in toughness and ductility. Friction coefficients decrease with longer annealing times, while surface damage is reduced. Wear is lower in softer material.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
P. Pereira, L. M. Vilhena, J. Sacramento, A. M. R. Senos, L. F. Malheiros, A. Ramalho
Summary: WC-based composites are widely used in mechanical applications due to their excellent wear and corrosion resistance. However, the use of cobalt as a binder poses supply risk and economic concerns. This study focuses on developing new cemented carbide grades to substitute cobalt binder and investigates their mechanical and tribological properties through wear tests and scratch tests.
Article
Nanoscience & Nanotechnology
Tian-tian Lu, Dong-peng Hua, Bai-Ling An, Muhammad Arslan Hafeez, Jie Pan, Li-Xue Chen, Jun-Yong Lu, Qing Zhou, Cheng Zhang, Lin Liu
Summary: In this study, a novel approach to enhance the anti-adhesive wear performance of rail in electromagnetic launching system is proposed by magnetron sputtering a W thin film onto the Al alloy surface. The results show that this approach can significantly reduce the interfacial energy of the rail/armature pair, leading to lower friction coefficient and alleviation in adhesion and mechanical damage of the Cu alloy. Molecular dynamics simulations reveal the formation of an amorphous interfacial layer during friction, which enables low friction by facilitating countermotion at the contacting surfaces.
SCRIPTA MATERIALIA
(2023)
Article
Engineering, Mechanical
S. Runge, P. A. Ignatyev, M. Wangenheim, C. Bederna, B. Wies, J. Wallaschek
Summary: Abrasive processes, specifically local slip, play a significant role in the friction and wear of vehicle tires. Understanding the dynamic contact between rubber blocks and abrasive surfaces is crucial for analyzing tire tread friction and wear mechanisms. Detailed consideration of realistic transient dynamics is essential for accurate characterization beyond typical abrasion testers.
Article
Engineering, Mechanical
Tshenolo Phinah Leso, Charles Witness Siyasiya, Roelf Johannes Mostert, Joseph Moema
Summary: The demand for railway services has increased, leading to higher speeds and axle loads. As a result, wheel and rail wear severity has increased. This study aimed to investigate the wear and rolling contact fatigue performance of class B wheels on R350HT and R260 rails under different slip ratios. The findings showed that wear severity was heavily influenced by the slip ratio. Additionally, the wear rate of class B wheels was found to be lower on R260 rail compared to R350HT rail. Three wear regimes, namely mild, severe, and catastrophic, were identified based on wear rate and wear index (T gamma/A).
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
D. W. Wang, F. Q. Li, X. Chen, Z. Y. Xiang, F. Zhao
Summary: A simple and effective method is used to construct graphene coating on brass surface, and the effect of electric currents on tribological performances are studied. Larger current can reduce the friction co-efficient and contact resistance, and suppress the generation of friction-induced vibration. Surface analysis shows that the graphene coating is seriously damaged at a low current input, resulting in an increase of friction coefficient and generation of vibration. Numerical analysis suggests that larger current can help reduce the contact pressure and improve wear, as well as expand the graphene coating, leading to better contact and exploitation of its properties.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Thermodynamics
Shuo Ma, Shilei Lu, Hongting Ma, Aobing Nong, Dandan Ma, Dawei Huang, Cong Yan
Summary: This study investigates the influence of active cooling on the rail thermal effect of an electromagnetic gun under single launch mode. Simulation and experimental results show that active cooling does not significantly affect the peak temperature and its location of the rail, but it improves the temperature distribution along the rail. The appropriate water flow velocity can accelerate the decrease of rail temperature.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Engineering, Mechanical
Huaidong Yang, Itzhak Green
Summary: This article derives analytical solutions to calculate the wear volume at the initiation of fretting motion and its early progression. The analytical results are verified by finite element analysis and the effects of plasticity on the wear volume are investigated.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Chemistry, Physical
Xiangdong Chang, Yuxing Peng, Zhencai Zhu, Hao Lu, Wei Tang, Xing Zhang
Summary: This study investigated the friction and wear behavior between wire rope and sheave under long-distance transmission conditions. The results showed that the sliding velocity had a significant impact on the COF, temperature rise, wear characteristics, and wear mechanisms of the wire rope. The study also found that surface wear affected the fracture behavior of the wire rope.
Article
Multidisciplinary Sciences
Justin D. Glover, Xingwei Yang, Rong Long, Jonathan T. Pham
Summary: Glover et al. investigate the lateral motion of microparticles on a soft, adhesive surface and find that a moving microparticle can induce a cease at the leading front of the surface due to compressive stress buildup. They also discover that the surface forms a self-contacting crease at the leading front, and simulations show that interfacial strength plays a dominant role in the formation of the crease. The crease then propagates through the contact zone in a Schallamach wave-like fashion, facilitated by free slip at the adhesive, self-contacting interface.
NATURE COMMUNICATIONS
(2023)
Article
Automation & Control Systems
Peipei Du, Junyong Lu, Xiangping Li, Junhong Feng, Kai Li
Summary: This article presents a three-dimensional transient electromagnetic (EM) force calculation model of the electromagnetic rail launcher (EMRL) and studies its interior ballistic characteristics, improving prediction accuracy and reliably calculating dynamic characteristics.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Engineering, Mechanical
Gan-Yun Huang, Yi-Ran Li
Summary: Friction is a common phenomenon in daily life and production, which can be either detrimental or beneficial. This study investigated the friction behavior at microscale using the JKR model and analogy with dislocation emission at crack tips, and proposed a mechanical model for rolling adhesion.
EXTREME MECHANICS LETTERS
(2021)
