Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-...Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-lar Weight Polyethylene(UHMWPE)fiber reinforcedPE tape prepared with the method of powder impregnat-ion was studied.The effect of impregnate length and thetensile force of the yarn on the fiber content as well as on the strength and modulus of the tape were discussed.Calculation shows that the strength and the modulus ofthe ULMWPE fiber can keep about 85％ after it undergothe process.展开更多
Dendrocalamus farinosus and Phyllostachys heterocycla bamboo logs were subjected to a novel treat- ment process for the preparation of bamboo fiber mats （BFMs）, and the obtained BFM were used to fabricate bamboo fib...Dendrocalamus farinosus and Phyllostachys heterocycla bamboo logs were subjected to a novel treat- ment process for the preparation of bamboo fiber mats （BFMs）, and the obtained BFM were used to fabricate bamboo fiber reinforced composite （BFRC）. We studied the mechanical properties of the BFRCs manufactured from the mats with and without bamboo nodes. The pres- ence of nodes in BFM greatly reduced tensile strength, compressive strength, modulus of elasticity, and modulus of rupture of the BFRCs, while the BFRCs fabricated from BFMs with nodes possessed higher horizontal shear strength. Therefore, the nodes in bamboo culms were an important factor in the uniform distribution of mechanical properties, and BFMs should be homogeneously arranged to reduce the impact of nodes on the mechanical strengths of BFRCs.展开更多
The corrosion evolution processes of steel reinforced concrete under simulated tidal and immersion zones of marine environment were investigated by using electrochemical measurements and corrosion morphology observati...The corrosion evolution processes of steel reinforced concrete under simulated tidal and immersion zones of marine environment were investigated by using electrochemical measurements and corrosion morphology observations. The results indicate that the corrosion of rebar in concrete under both environments experiences the deterioration from passivation to pitting corrosion and then to general corrosion. Specially, the pitting plays the major role only in the early stage of corrosion, and the general corrosion replaces the dominate role of pitting during the long-term corrosion. In addition, both the pitting depth on local surface and the rust thickness on the overall surface of rebar in the tidal condition are larger than those in immersion condition, which is attributed to the faster corrosion rate in tidal zone caused by the concentrated chloride ions and sufficient oxygen supply.展开更多
Carbon fiber reinforced polymers （CFRPs） are known to be difficult to cut due to the abrasive nature of carbon fibers and the low thermal conductivity of the polymer matrix. Polycrystalline diamond （PCD） drills ar...Carbon fiber reinforced polymers （CFRPs） are known to be difficult to cut due to the abrasive nature of carbon fibers and the low thermal conductivity of the polymer matrix. Polycrystalline diamond （PCD） drills are commonly employed in CFRP drilling to satisfy hole quality conditions with an acceptable tool life. Drill geometry is known to be influential on the hole quality and productivity of the process. Considering the variety of CFRP laminates and available PCD drills on the market, selecting the suitable drill design and process parameters for the CFRP material being machined is usually per- formed through trial and error, In this study, machining performances of four different PCD drills are investigated. A mechanistic model of drilling is used to reveal trade-offs in drill designs and it is shown that it can be used to select suitable feed rate for a given CFRP drilling process.展开更多
文摘Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-lar Weight Polyethylene(UHMWPE)fiber reinforcedPE tape prepared with the method of powder impregnat-ion was studied.The effect of impregnate length and thetensile force of the yarn on the fiber content as well as on the strength and modulus of the tape were discussed.Calculation shows that the strength and the modulus ofthe ULMWPE fiber can keep about 85％ after it undergothe process.
基金financially supported by the Key Laboratory of Wood Industry and Furniture Engineering of Sichuan Provincial Colleges and Universitiesthe National Forestry Public Welfare Scientific Research Program(201304503)the Science and Technology Innovation Foundation for College Students
文摘Dendrocalamus farinosus and Phyllostachys heterocycla bamboo logs were subjected to a novel treat- ment process for the preparation of bamboo fiber mats （BFMs）, and the obtained BFM were used to fabricate bamboo fiber reinforced composite （BFRC）. We studied the mechanical properties of the BFRCs manufactured from the mats with and without bamboo nodes. The pres- ence of nodes in BFM greatly reduced tensile strength, compressive strength, modulus of elasticity, and modulus of rupture of the BFRCs, while the BFRCs fabricated from BFMs with nodes possessed higher horizontal shear strength. Therefore, the nodes in bamboo culms were an important factor in the uniform distribution of mechanical properties, and BFMs should be homogeneously arranged to reduce the impact of nodes on the mechanical strengths of BFRCs.
基金financially supported by the National Natural Science Foundation of China (Nos. 51501201, 51501204 and 51671200)the National Key Research and Development Program of China (No. 2017YFB0702302)
文摘The corrosion evolution processes of steel reinforced concrete under simulated tidal and immersion zones of marine environment were investigated by using electrochemical measurements and corrosion morphology observations. The results indicate that the corrosion of rebar in concrete under both environments experiences the deterioration from passivation to pitting corrosion and then to general corrosion. Specially, the pitting plays the major role only in the early stage of corrosion, and the general corrosion replaces the dominate role of pitting during the long-term corrosion. In addition, both the pitting depth on local surface and the rust thickness on the overall surface of rebar in the tidal condition are larger than those in immersion condition, which is attributed to the faster corrosion rate in tidal zone caused by the concentrated chloride ions and sufficient oxygen supply.
文摘Carbon fiber reinforced polymers （CFRPs） are known to be difficult to cut due to the abrasive nature of carbon fibers and the low thermal conductivity of the polymer matrix. Polycrystalline diamond （PCD） drills are commonly employed in CFRP drilling to satisfy hole quality conditions with an acceptable tool life. Drill geometry is known to be influential on the hole quality and productivity of the process. Considering the variety of CFRP laminates and available PCD drills on the market, selecting the suitable drill design and process parameters for the CFRP material being machined is usually per- formed through trial and error, In this study, machining performances of four different PCD drills are investigated. A mechanistic model of drilling is used to reveal trade-offs in drill designs and it is shown that it can be used to select suitable feed rate for a given CFRP drilling process.
