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Improving Interfacial Interactions of CF/PEEK Composites with Sulfonated Polyether Sulfone
Tianning Ren,Guangming Zhu,Xiaoming Ren,Renjie Tian,Ben Li 한국섬유공학회 2021 Fibers and polymers Vol.22 No.1
Due to the limitation of surface inertness and wettability of carbon fibers (CF), the adhesion between Poly(etherether-ketone) (PEEK) resin matrix and CF is poor, which reduces the mechanical properties of CF/PEEK composites. Inorder to improve the interfacial performance between PEEK matrix and carbon fiber fabric, sulfonated-polyether-sulfone (s-PSF) was coated as a sizing agent on the surface of the carbon fiber to construct CF/PEEK composite interface. On one hand,the formation of hydrogen bonds between s-PSF and activated CF increases the adhesion between s-PSF and fibers. On theother hand, Good compatibility between S-PSF and PEEK, which improves the interface performance between PEEK andCF. The results showed that the mechanical properties and interface properties of CF/PEEK composite prepared by modifiedCF were improved to some extent. The flexural strength, flexural modulus, impact strength and interlaminar shear strength ofthe materials were increased by 57.5 %, 16.7 %, 44.2 % and 39.7 %, respectively. By introducing s-PSF as sizing agent intoCF/PEEK composite interface, the comprehensive properties of the material were effectively improved.
Guangming Zheng,Xiang Cheng,Li Li,Rufeng Xu,Yebing Tian 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1
The high-speed dry milling of AISI 4340 steel was carried out with a CVD Al 2 O 3 /TiCN coated carbide tool. The relationships between cutting force, surface roughness and cutting parameter were conducted, and the influence of tool wear on cutting force and surface roughness was also investigated. The wear mechanism of coated tool was revealed by SEM micrograph and EDS analysis. Due to the lower tool wear rate, the increase of cutting forces and surface roughness R a was smaller at the initial wear stage and the steady wear stage, whereas the increase of cutting forces was improved suddenly when the flank wear was more than 0.25 mm. Additionally, the coated tool wear was mainly caused by adhesion, abrasion, oxidation and diffusion, accompanied with a little peeling and chipping. The research results are expected to provide optimum cutting parameters for high-efficiency machining of high-strength steel.
Influence of graphene oxide on the heat resistance of high strength concrete
Guangming Meng,Yuwu Sui,Shu Liu,Qingbo Tian,Xinling Cui,Yuejian Wu 한양대학교 청정에너지연구소 2022 Journal of Ceramic Processing Research Vol.23 No.6
The effect of Graphene Oxide (GO) on the thermal properties of high-strength concrete has been less studied. The mechanicalproperties, compactness, mineral composition and microstructure of the high-strength concrete with GO addition wereexamined by heat treatments at different temperatures. The results showed that the enhancement of the residual flexuralstrength with GO addition was greater than that of the residual compressive strength; GO addition had a significant effecton the mechanical properties of concrete treated at less than 500 ℃; Differential Scanning Calorimeter (DSC) test showed thatthe high-strength concrete with GO addition required more heats for its decomposition after 500 ℃; The internal pores/cracksof the high strength concrete with GO addition were reduced after the heat treatment at a high-temperature because theproducing of new crystals can improve the residual properties of the high-strength concrete.
Zhenze Liu,Qing Yuan,Guangming Nie,Yantao Tian 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.2
In order to be acceptable to drivers, the adaptive cruise control (ACC) systems need to be designed based on the analysis of human driver driving behavior. A new safe distance model is proposed in this paper based on the analysis of real-world driving test data. The goal of the control algorithm is to achieve naturalistic behavior of the vehicle that can comprehensively address the issue of driving safety, tracking performance, fuel economy and ride comfort. Firstly, a hierarchical control architecture is utilized which lower controller compensates for nonlinear vehicle dynamics and enables tracking of the desired acceleration. Then the acceleration rate of the following vehicle is introduced as state variables in the model of the car-following system for a more realistic and comprehensive description of dynamic evolution between the preceding car and the following car. Next, the control objectives above are formulated into a constrained quadratic programming problem under the framework of model predictive control (MPC). Finally, the simulation results show that the control strategy proposed in this paper can provide natural following performance that not only can satisfy driving safety, tracking performance but also can achieve fuel economy and ride comfort.