Yan Chun

Chinese Academy of Sciences | CAS · Academy of Opto-Electronics (AOE)

Existing hot stamping simulations are performed at the macroscopic scale, making optimizing process parameters for a new composite system time‐consuming. This paper develops a dual‐scale three‐dimensional thermos‐viscoelastic model based on a numerical homogenization approach to accurately predict the structural deformation of thermoplastic composi...

In this study, a novel functionalized graphene oxide (F‐GO) modified polyamide 6 (PA6) sizing agent is developed to improve the interfacial and mechanical properties of carbon fiber (CF) reinforced PA6 composites. To enhance compatibility between GO and sizing agent, PA6 molecular chains are covalently grafted onto the GO sheets in advance. The res...

Carbon fiber is an ideal candidate for preparing electrode of structural supercapacitors, while its low specific surface area is a vital factor which restricts energy storage performance. In this study, MnOOH nanowires (MnOOH‐NWs) are in‐situ deposited onto the woven carbon fiber fabric (WCF) surface through an effective one‐step hydrothermal treat...

Exit-chipping of the drilled hole produced in rotary ultrasonic drilling (RUD) process significantly influences the assembly accuracy and technological performance of the sapphire components. To reduce or eliminate the exit-chipping of the RUD hole, an efficient prediction model should be established to facilitate the optimization of the drilling p...

The halogen-free flame-retardant continuous glass fiber/polyamide 6 (GF/PA6) composites containing hexaphenoxycyclotriphosphazene (HPCTP) were prepared by the resin transfer molding (RTM) process. The influence of HPCTP content on mechanical properties of GF/PA6 composites was studied. The addition of HPCTP has no obvious effect on the tensile prop...

In this study, a nickel coated carbon fiber (Ni-CF) tow is used to enable glass fiber reinforced plastics (GFRPs) to exhibit multi-functional properties with self-diagnosing function. The experimental results indicate that the Ni-CF exhibits desirable interfacial compatibility with the matrix resin and has no negative effect on the performance of G...

The interfacial properties between carbon fiber (CF) and polymer matrix are critical to the performance of CF reinforced composites. Herein, we reported a new method of tailoring the interfacial properties by grafting graphene oxide (GO) onto the CF surface with hyperbranched polyglycerol (HPG), which could improve the interfacial shear strength (I...

This investigation represented a fundamental research on the potential effects of the high-frequency vibration on the hole integrity involved in rotary ultrasonic drilling (RUD) of carbon fiber-reinforced plastic (CFRP) composites. It was found the increased thickness of the CFRP plate shrunk the flowing velocity of the coolant, which brought about...

The cyclomatrix-type polyphosphazene is hypothesized to have potential as optical material due to the existing of transparent P=N ring skeleton. However, as an insoluble and infusible cross-linked polymer, cyclomatrix-type polyphosphazene is very difficult to be processed into film coatings. Herein, we reported a facile in situ template method to p...

Carbon fiber (CF) reinforced polyamide 6 (PA6) composite has an extensive application. However, the performances of CF/PA6 composite are constrained by the poor interfacial adhesion between CF and PA6 matrix. In this article, in order to strengthen the interfacial adhesion of CF/PA6 composite, a layer of poly(cyclotriphosphazene‐co ‐4,4′‐sulfonyldi...

In this paper, the manufacturing and mechanical properties of steel-carbon fiber reinforced polymer (CFRP) hybrid composites were investigated. Steel-CFRP hybrid composites with different manufacturing processes were prepared to obtain different shear strength based on steel surface treatment (abrasion and grit blasting) and adhesive-bonding proces...

In this work Tailored Variable Angle Tow (VAT) patches with various layup directions are employed to reinforce open-hole carbon fiber composite laminates and the tensile behaviour of the reinforced laminates is investigated. The relationship between the tensile behaviour of the reinforced laminate and the fiber orientation of the VAT reinforcement...

This paper presented a fundamental investigation of the exit-chipping formation mechanisms involved in rotary ultrasonic drilling (RUD) and conventional drilling (CD) of glass BK7 processes. It was found that the mutual tool-material extrusion initially activated the subsurface crack with the maximum depth (incipient crack) located at the margin of...

Material removal in rotary ultrasonic machining (RUM) of hard-brittle material is an abnormal complicated process, which involves the combination effects of the numerous abrasive grains with the random distributions in the dimensions and penetration depths. These stochastic characteristics result in the evident differences in the extrusion loading...

This investigation presented a quantitative evaluation technique of the hole entrance chippings with respect to the image processing technology. Considering the nucleation and propagation processes of lateral cracks, the chipping formation mechanisms involved in rotary ultrasonic drilling of glass BK7 were also explored incorporated with the abrasi...

The mechanical properties of carbon fiber (CF) reinforced composites are greatly dependent on the interfacial adhesion between fiber and resin matrix. Introducing nanoscale reinforcements into the interface is an effective approach to improve the interfacial adhesion of CF composites. In this paper, we proposed a facile and effective method for ass...

We successfully prepared a graphene‐modified carbon fiber (CF) sizing agent with good dispersity and stability by dispersing reduced graphene oxide (RGO) into an emulsion‐type sizing agent. RGO was obtained by the reduction of graphene oxide (GO) with the help of gallic acid. The influence of the graphene‐modified sizing agent on the interfacial pr...

In case of Self-reinforced polymer composites (SRCs) the fibres and matrix belong to the same family of polymers that can ensure 100% recyclability as compared to traditional fibre reinforced epoxy matrix based composites. Most of the SRCs were studied only on material bases not structural bases, although some structures were fabricated but most of...

Graphene oxide (GO) was grafted onto the surface of carbon fiber (CF) by two synthetic routes with hexamethylene diisocyanate (HDI) tripolymer as the coupling agent. The first one was to use HDI tripolymer to modify the surface of GO, named GO-NCO, and then graft GO-NCO onto the oxidized carbon fiber surface. The other route was to use HDI tripolym...

The paper proposes the novel Variable Angle Tow (VAT) placement technique to create local reinforcement on fiber reinforced composites with holes which enables to optimize the design for variable stiffness laminates by placing continuous fiber to follow the pre-calculated principle stress trajectories automatically. The potential factors influencin...

Continuous glass fiber (GF)-reinforced polymerized cyclic butylene terephthalate (pCBT) composites were prepared via vacuum-assisted resin transfer molding using butyltin tris(2-ethylhexanoate) as the catalyst. The relationship between melt viscosity and polymerization time was examined in the ring-opening polymerization of CBT resin. The effects o...

Introducing nanoscale reinforcements into the interface between carbon fiber (CF) and resin is an effective approach to improve the interfacial adhesion of CF composites. In this paper, a facile one-pot polymerization process provides a rapid and efficient method for preparing polyphosphazene microspheres/CF hybrid reinforcement using hexachlorocyc...

A family of curves based fiber path optimization approach is developed to optimize the fiber paths in composite laminate with a centered hole, in an attempt to improve the uniaxial tensile load carrying capabilities. In the proposed optimization method, a novel family of curves with two design variables is assumed to approximate the fiber paths in...

To improve the interfacial adhesion of carbon fiber reinforced polymer composites (CFRP), carbon fiber usually has to be carried out surface treatment under harsh conditions. However, enhancing the interfacial property is usually accompanied by deteriorating tensile strength of carbon fiber, due to some defects on fiber surfaces after surface modif...

A series of novel wholly aromatic copolyamides, poly(p-phenylene terephthalamide)-ran-poly[p-phenylene 2,5-bis(allyloxy)terephthalamide] (APPTA-x, x (=0, 5, 25, 50, 60, 75, 90, and 100) represents the molar fraction of allyloxy containing structure unit), were prepared via low temperature solution copolycondensation of p-phenylenediamine, terephtha...

Liquid composite moulding (LCM) has been successfully used to manufacture natural fiber reinforced composites. Effects of liquid absorption and swelling on the permeability of natural fiber fabrics in LCM were investigated. It shows that the saturated permeability measured in the corn syrup is 23.1–69.5% smaller than that in the motor oil because o...

To improve the interfacial properties of carbon fiber (CF) reinforced composites, an innovative and simple functionalized strategy has been proposed by grafting 4,4′-oxydianiline (ODA) onto carbon fiber surface using hexachlorocyclophosphazene (HCCP) as a novel coupling agent at mild reaction conditions. The chemical composition of the CF surface w...

Tailoring of composite laminated panels by Variable Angle Tow (VAT) steering fibers in their optimal spatial orientations provides a unique opportunity to maximize performance. Increased buckling response of the laminates by VAT steering technique may directly provide significant weight savings by redistributing loads in a benign manner. The aim of...

Continuous glass fiber (GF) reinforced anionic polyamide-6 (APA6) composites were prepared via in situ ring-opening polymerization of caprolactam monomers. The effects of catalyst content, polymerization temperature and time on the viscosity average molar mass (Mv) and degree of crystallinity (Xc) were investigated in detail. The final mechanical p...

In this study, a new and facile route has been developed to prepare graphene oxide (GO) reinforced polyamide 6 (PA6) composites and synthesize simultaneously PA6 grafted GO hybrid materials: ε-caprolactam (CL) was firstly fixed onto the GO sheets coupling by 4,4′-methylenebis(phenyl isocyanate), and then PA6 was grafted from the GO surface by in si...

A numerical procedure for predicting the orthotropic mechanical properties of plain-weave composites with matrix voids through a combined approach of the representative volume element method and finite element analyses is presented. The representative volume element method was implemented using two unit cells established at different length scales...

Continuous glass fiber (GF) reinforced poly(cyclic butylene terephthalate) (PCBT) composites were prepared via in-situ polymerization of cyclic butylene terephthalate (CBT). The effects of the catalyst contents on the crystallinity and the mechanical properties of GF/PCBT composites were studied. When the catalyst mass fraction reaches 0.5%, the cr...

The performance of carbon fiber-reinforced composites is dependent to a great extent on the properties of fiber-matrix interface. To improve the interfacial properties in carbon fiber/epoxy composites, we directly introduced graphene oxide (GO) sheets dispersed in the fiber sizing onto the surface of individual carbon fibers. The applied graphite o...

Three bisphenol A diphthalimide bisbenzoxazine monomers were successfully synthesized through a two-step procedure. First, a new bihydric phenol, bishydroxyphenyl bisphenol A diphthalimide, was prepared from bisphenol A dianhydride and 4-aminophenol. Then, different bisphenol A diphthalimide bisbenzoxazine monomers were synthesized from bishydroxyp...

A series of the surface-functionalized nano-SiO2/polybenzoxazine (PBOZ) composites was produced, and an attempt was made to improve the toughness of PBOZ material, without sacrificing other mechanical and thermal properties. A benzoxazine functional silane coupling agent was synthesized to modify the surface of nano-SiO2 particles, which were then...

Honeycomb sandwich materials have been widely used in aerospace industry as secondary structural materials or interior panels. Recently the research of full thermoplastic honeycomb sandwich materials has been of interest due to their recyclability. In their production, they usually demand an adhesive-free process, namely fusion bonding, to connect...