A Study on the Mechanical Properties of Tire in the High-Speed Frontal Impact Condition

Author(s):  
Fangxia Yang ◽  
Taisong Cui ◽  
Bo Dian ◽  
Bo Wei
2014 ◽  
Vol 66 (4) ◽  
pp. 520-524 ◽  
Author(s):  
Serkan Büyükdoğan ◽  
Süleyman Gündüz ◽  
Mustafa Türkmen

Purpose – The paper aims to provide new observations about static strain ageing in aluminium (Al) alloys which are widely used in structural applications. Design/methodology/approach – The present work aims to provide theoretical and practical information to industries or researchers who may be interested in the effect of static strain ageing on mechanical properties of Al alloys. The data are sorted into the following sections: introduction, materials and experimental procedure, results and discussion and conclusions. Findings – Tensile strength, proof strength (0.2 per cent) and percentage elongation measurement were used to investigate the effect of strain ageing on the mechanical properties. Wear tests were performed by sliding the pin specimens, which were prepared from as-received, solution heat-treated, deformed and undeformed specimens after ageing, on high-speed tool steel (64 HRC). It is concluded that the variations in ageing time improved the strength and wear resistance of the 6063 Al alloy; however, a plastically deformed solution-treated alloy has higher strength and wear resistance than undeformed specimens for different ageing times at 180°C. Practical implications – A very useful source of information for industries using or planning to produce Al alloys. Originality/value – This paper fulfils an identified resource need and offers practical help to the industries.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1134
Author(s):  
Bo Seok Song ◽  
Jun Young Lee ◽  
Sun Hwa Jang ◽  
Wan-Gyu Hahm

High-speed melt spinning of thermotropic liquid crystalline polymer (TLCP) resin composed of 4-hydroxybenzoic acid (HBA) and 2-hydroxy-6-napthoic acid (HNA) monomers in a molar ratio of 73/27 was conducted to investigate the characteristic structure development of the fibers under industrial spinning conditions, and the obtained as-spun TLCP fibers were analyzed in detail. The tensile strength and modulus of the fibers increased with shear rate in nozzle hole, draft in spin-line and spinning temperature and exhibited the high values of approximately 1.1 and 63 GPa, respectively, comparable to those of industrial as-spun TLCP fibers, at a shear rate of 70,000 s−1 and a draft of 25. X-ray diffraction demonstrated that the mechanical properties of the fibers increased with the crystalline orientation factor (fc) and the fractions of highly oriented crystalline and non-crystalline anisotropic phases. The results of structure analysis indicated that a characteristic skin–core structure developed at high drafts (i.e., spinning velocity) and low spinning temperatures, which contributed to weakening the mechanical properties of the TLCP fibers. It is supposed that this heterogeneous structure in the cross-section of the fibers was induced by differences in the cooling rates of the skin and core of the fiber in the spin-line.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Qingzhong Mao ◽  
Yusheng Zhang ◽  
Yazhou Guo ◽  
Yonghao Zhao

AbstractThe rapid development of high-speed rail requires copper contact wire that simultaneously possesses excellent electrical conductivity, thermal stability and mechanical properties. Unfortunately, these are generally mutually exclusive properties. Here, we demonstrate directional optimization of microstructure and overcome the strength-conductivity tradeoff in copper wire. We use rotary swaging to prepare copper wire with a fiber texture and long ultrafine grains aligned along the wire axis. The wire exhibits a high electrical conductivity of 97% of the international annealed copper standard (IACS), a yield strength of over 450 MPa, high impact and wear resistances, and thermal stability of up to 573 K for 1 h. Subsequent annealing enhances the conductivity to 103 % of IACS while maintaining a yield strength above 380 MPa. The long grains provide a channel for free electrons, while the low-angle grain boundaries between ultrafine grains block dislocation slip and crack propagation, and lower the ability for boundary migration.


2021 ◽  
Vol 1121 (1) ◽  
pp. 012009
Author(s):  
S Lee ◽  
R Muchime ◽  
R Matsumoto ◽  
H Utsunomiya

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 559
Author(s):  
Lakshminath Kundanati ◽  
Prashant Das ◽  
Nicola M. Pugno

Aquatic predatory insects, like the nymphs of a dragonfly, use rapid movements to catch their prey and it presents challenges in terms of movements due to drag forces. Dragonfly nymphs are known to be voracious predators with structures and movements that are yet to be fully understood. Thus, we examine two main mouthparts of the dragonfly nymph (Libellulidae: Insecta: Odonata) that are used in prey capturing and cutting the prey. To observe and analyze the preying mechanism under water, we used high-speed photography and, electron microscopy. The morphological details suggest that the prey-capturing labium is a complex grasping mechanism with additional sensory organs that serve some functionality. The time taken for the protraction and retraction of labium during prey capture was estimated to be 187 ± 54 ms, suggesting that these nymphs have a rapid prey mechanism. The Young’s modulus and hardness of the mandibles were estimated to be 9.1 ± 1.9 GPa and 0.85 ± 0.13 GPa, respectively. Such mechanical properties of the mandibles make them hard tools that can cut into the exoskeleton of the prey and also resistant to wear. Thus, studying such mechanisms with their sensory capabilities provides a unique opportunity to design and develop bioinspired underwater deployable mechanisms.


Author(s):  
O Kocar ◽  
H Livatyalı

An aluminized 22MnB5 (Boron) steel sheet, used for structural parts in the automotive industry, was subjected to press-hardening followed by austenitizing, both in a conventional furnace and via the conductive (electric resistance) heating method, an innovative technique based on the Joule’s principle for fast heating of the sheet metal. Conductive heating presents a number of advantages over the in-furnace heating method. These include a more efficient use of energy, as well as the requirement of less time and space for heating, thus lowering costs. After press-hardening was performed using both methods, the microstructural and mechanical characterizations of both specimens were examined for optical microscopy, hardness, tensile strength, and high-speed impact tests. The results showed that the press-hardening process transformed the ferritic–pearlitic microstructure in the as-received state into martensite after die quenching and caused a substantial increase in hardness and strength at the expense of ductility and impact toughness. On the other hand, no significant difference was observed in either the microstructure or mechanical properties with respect to the heating method used. The results obtained in the present investigation concur with the findings of current literature.


2001 ◽  
Vol 72 (2) ◽  
pp. 58-65 ◽  
Author(s):  
Saied El-Ghazaly ◽  
Tarek EI-Gammal ◽  
Ahmed EI-Sabbagh ◽  
Adel Nofal ◽  
Mohammed Abbas

2008 ◽  
Vol 367 ◽  
pp. 125-136 ◽  
Author(s):  
Lorenzo Donati ◽  
Luca Tomesani

This work summarizes the outcome of recent research by the authors on modeling the formation of seam welds in aluminum extrusion and on evaluating the related mechanical properties on the final products. A profile with a seam weld in the middle section was produced with different die designs in order to investigate the relation between die design and local welding parameters, such as contact pressure, temperature, time of contact, strain and strain rate paths. The local welding conditions were evaluated by complete thermo-mechanical 3D FEM simulation of the processes. Specimens were extracted from the profiles and tensile tested, the resulting mechanical properties being discussed with respect to the local welding conditions. The possibility to adopt criteria for assessing the welding quality is discussed, together with the effect of high speed damage cracking.


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