In literature review,experimental work and finite element analysis was carried out as per ASTM 1425 and ASTM 2344 to understand the distribution of ILSS(interlaminar shear strength)in S glass epoxy composite for thin ...In literature review,experimental work and finite element analysis was carried out as per ASTM 1425 and ASTM 2344 to understand the distribution of ILSS(interlaminar shear strength)in S glass epoxy composite for thin and thick laminates.Comparison of the ASTM methods is made and ASTM 1425 is recommended since sustainability can be achieved while understanding the properties of the composite.The objective of the present work is to estimate ILSS in CNT(carbon nanotube)reinforced S glass epoxy composites by finite element analysis.展开更多
The interlaminar shear property of composites remains a serious concern in application. In this article, five different multiwalled carbon nanotubes （MWCNTs） are tried to improve the interlaminar shear property of c...The interlaminar shear property of composites remains a serious concern in application. In this article, five different multiwalled carbon nanotubes （MWCNTs） are tried to improve the interlaminar shear property of composites, including two MWCNTs （MWCNTs-A and MWCNTs-B） different with diameters and lengths, an orientated MWCNTs （MWCNTs-C）, a film-shaped MWCNTs-A （MWCNTs-D）, and a surface-treated MWCNTs-B （MWCNTs-E）, The interlaminar shear strength （ILSS） of the composites, filled with one of the above-mentioned materials as a constituent is investigated. The best ILSS increases by 8.16% from 24,5 MPa to 26.5 MPa with MWCNTs-E. In addition, the dispersion of MWCNTs in a glass fiber-reinforced polymer （GFRP） is researched by a scanning electron microscopy （SEM） in association with the ILSS results.展开更多
In this present work siliconized e-glass fibre reinforced epoxy resin composite has been prepared and compared with acid and base treated e-glass fibre epoxy composites to know the significant advantage of silane trea...In this present work siliconized e-glass fibre reinforced epoxy resin composite has been prepared and compared with acid and base treated e-glass fibre epoxy composites to know the significant advantage of silane treatment on fibre. The composites were fabricated by laying 20, 30 and 40vol% of e-glass fibre into epoxy resin matrix. The e-glass fibre woven mat was surface treated by an amine functional coupling agent 3-Aminopropyletrimethoxysilane(APTMS). The fibres were surface treated by aqueous solution method and thermo assisted to create silinol groups. Similarly for acid treatment H_2SO_4 and base treatment Na OH with 1N concentration was used for surface treating the fibres. Effectiveness of silane treatment on glass fibre was compared by inter laminar shear strength test according to ASTM D 2344.Drilling process with varying diameter drill bit and varying cutting speed was applied to check the composites for their delamination resistance while machining. Maximum improvement of 15%, 12.5% and9%(20, 30 and 40 vol %) on ILSS was achieved for siliconized e-glass fibre reinforced epoxy composites.The scanning electron microscopy images revealed that no fibre pull out was present on fractured surfaces of composites which contains siliconized e-glass fibre. Similarly better dimensional accuracy was achieved on drilling process for composites contains siliconized e-glass fibre.展开更多
Interlaminar shear properties of the fibre reinforced polymer composites are very important in many structured applications. It has been reported that interlaminar shear strength (ILSS) of fibre reinforced polymer com...Interlaminar shear properties of the fibre reinforced polymer composites are very important in many structured applications. It has been reported that interlaminar shear strength (ILSS) of fibre reinforced polymer composites may be improved by the modification of the matrix. In this paper, diglycidyl ether of bisphenol A (DGEBA)/triethylene tetramine (TETA) system is used as the starting epoxy matrix. Alumina nanoparticles are employed to modify the epoxy matrix at various concentrations. Unmodified and modified epoxy resins are used along with unidirectional glass fibres for fabricating composite laminates by vaccum bagging method. The interlaminar shear strength of the glass fibre reinforced composites is investigated and the results indicate that introduction of the alumina nanoparticles enhances the ILSS. In particular, the addition of 0.8 wt% alumina nanoparticles leads to maximum enhancement in the ILSS;however, there is a decrease in the value with further addition. The dispersion of alumina nanoparticles and the fracture surfaces of the fibre reinforced composites are examined by the scanning electron microscope. The graphs are employed to explain the results.展开更多
The paper presented accelerated ageing test results of a durability study on ortho-phthalic anhydride-type unsaturated polyester resin （191#） and its glass-fiber reinforcement polyester composites （GFRPC）. The sam...The paper presented accelerated ageing test results of a durability study on ortho-phthalic anhydride-type unsaturated polyester resin （191#） and its glass-fiber reinforcement polyester composites （GFRPC）. The samples were exposed in an artificial xenon arc lamp ageing cell or a thermo-oxidative ageing cell. Morphology and gloss of the specimens were investigated by using a microscope and a gloss-meter, respectively. The tensile strength, bending strength and inter-laminar shear strength （ILSS） of GFRPC were tested before and after exposure, and were considered to evaluate the durability performance of this material. The polyester resin was analyzed by fourier transform infrared （FT-IR） spectroscopy. The results showed that the glossiness of the specimens got worse and some cracks appeared on their surface during the course of ageing, the tensile strength and bending strengths of the specimens first increased and then decreased. The ILSS of the composites decreased after they were aged in the xenon arc lamp cell, but increased while they were aged in the thermo-oxidative cell. The changes of these trends become more obvious during ageing in the xenon arc lamp cell, so the main influencing factor leading to the failure of this material is UV irradiation.展开更多
Pharmaceuticals and personal care products(PPCPs)are a unique group of emerging and nonpersistent contaminants.In this study,27 PPCPs in various water samples were extracted by solid phase extraction(SPE),and determin...Pharmaceuticals and personal care products(PPCPs)are a unique group of emerging and nonpersistent contaminants.In this study,27 PPCPs in various water samples were extracted by solid phase extraction(SPE),and determined by isotope dilution method using liquid chromatography coupled to tandem triple quadruple mass spectrometer(LC-MS/MS).A total of 27 isotopically labeled standards(ILSs)were applied to correct the concentration of PPCPs in spiked ultrapure water,drinking water,river,effluent and influent sewage.The corrected recoveries were 73%-122%with the relative standard deviation(RSD)<16%,except for acetaminophen.The matrix effect for all kinds of water samples was<22%and the method quantitation limits(MQLs)were 0.45-8.6 ng/L.The developed method was successfully applied on environmental water samples.The SPE extracts of spiked ultrapure water,drinking water,river and wastewater effluent were stored for 70 days,and the ILSscorrected recoveries of 27 PPCPs were obtained to evaluate the correction ability of ILSs in the presence of variety interferences.The recoveries of 27 PPCPs over 70 days were within the scope of 72%-140%with the recovery variation<37%in all cases.The isotope dilution method seems to be of benefit when the extract has to be stored for long time before the instrument analysis.展开更多
It is well known that voids have detrimental effects on the performance of composites. This study aims to provide a practical method for predicting the effects of process induced voids on the properties of composites....It is well known that voids have detrimental effects on the performance of composites. This study aims to provide a practical method for predicting the effects of process induced voids on the properties of composites. Representative volume elements （RVE） for carbon fibre/epoxy composites of various fibre volume fractions and void contents are created, and the moduli and strengths are derived by finite element anal- ysis （FEA）. Regression models are fitted to the FEA data for predicting composite properties including tensile, compressive and shear. The strengths of composite laminates including tensile strngth and interlaminar shear strength （ILSS） are calculated with the aid of the developed models. The model predictions are compared with various experimental data and good agreement is found. The outcome from this study provides a useful optimisation and robust design tool for realising affordable composite prod- ucts when process induced voids are taken into account.展开更多
文摘In literature review,experimental work and finite element analysis was carried out as per ASTM 1425 and ASTM 2344 to understand the distribution of ILSS(interlaminar shear strength)in S glass epoxy composite for thin and thick laminates.Comparison of the ASTM methods is made and ASTM 1425 is recommended since sustainability can be achieved while understanding the properties of the composite.The objective of the present work is to estimate ILSS in CNT(carbon nanotube)reinforced S glass epoxy composites by finite element analysis.
文摘The interlaminar shear property of composites remains a serious concern in application. In this article, five different multiwalled carbon nanotubes （MWCNTs） are tried to improve the interlaminar shear property of composites, including two MWCNTs （MWCNTs-A and MWCNTs-B） different with diameters and lengths, an orientated MWCNTs （MWCNTs-C）, a film-shaped MWCNTs-A （MWCNTs-D）, and a surface-treated MWCNTs-B （MWCNTs-E）, The interlaminar shear strength （ILSS） of the composites, filled with one of the above-mentioned materials as a constituent is investigated. The best ILSS increases by 8.16% from 24,5 MPa to 26.5 MPa with MWCNTs-E. In addition, the dispersion of MWCNTs in a glass fiber-reinforced polymer （GFRP） is researched by a scanning electron microscopy （SEM） in association with the ILSS results.
文摘In this present work siliconized e-glass fibre reinforced epoxy resin composite has been prepared and compared with acid and base treated e-glass fibre epoxy composites to know the significant advantage of silane treatment on fibre. The composites were fabricated by laying 20, 30 and 40vol% of e-glass fibre into epoxy resin matrix. The e-glass fibre woven mat was surface treated by an amine functional coupling agent 3-Aminopropyletrimethoxysilane(APTMS). The fibres were surface treated by aqueous solution method and thermo assisted to create silinol groups. Similarly for acid treatment H_2SO_4 and base treatment Na OH with 1N concentration was used for surface treating the fibres. Effectiveness of silane treatment on glass fibre was compared by inter laminar shear strength test according to ASTM D 2344.Drilling process with varying diameter drill bit and varying cutting speed was applied to check the composites for their delamination resistance while machining. Maximum improvement of 15%, 12.5% and9%(20, 30 and 40 vol %) on ILSS was achieved for siliconized e-glass fibre reinforced epoxy composites.The scanning electron microscopy images revealed that no fibre pull out was present on fractured surfaces of composites which contains siliconized e-glass fibre. Similarly better dimensional accuracy was achieved on drilling process for composites contains siliconized e-glass fibre.
文摘Interlaminar shear properties of the fibre reinforced polymer composites are very important in many structured applications. It has been reported that interlaminar shear strength (ILSS) of fibre reinforced polymer composites may be improved by the modification of the matrix. In this paper, diglycidyl ether of bisphenol A (DGEBA)/triethylene tetramine (TETA) system is used as the starting epoxy matrix. Alumina nanoparticles are employed to modify the epoxy matrix at various concentrations. Unmodified and modified epoxy resins are used along with unidirectional glass fibres for fabricating composite laminates by vaccum bagging method. The interlaminar shear strength of the glass fibre reinforced composites is investigated and the results indicate that introduction of the alumina nanoparticles enhances the ILSS. In particular, the addition of 0.8 wt% alumina nanoparticles leads to maximum enhancement in the ILSS;however, there is a decrease in the value with further addition. The dispersion of alumina nanoparticles and the fracture surfaces of the fibre reinforced composites are examined by the scanning electron microscope. The graphs are employed to explain the results.
基金supported by the National Natural Science Foundation of China (No.50533060)
文摘The paper presented accelerated ageing test results of a durability study on ortho-phthalic anhydride-type unsaturated polyester resin （191#） and its glass-fiber reinforcement polyester composites （GFRPC）. The samples were exposed in an artificial xenon arc lamp ageing cell or a thermo-oxidative ageing cell. Morphology and gloss of the specimens were investigated by using a microscope and a gloss-meter, respectively. The tensile strength, bending strength and inter-laminar shear strength （ILSS） of GFRPC were tested before and after exposure, and were considered to evaluate the durability performance of this material. The polyester resin was analyzed by fourier transform infrared （FT-IR） spectroscopy. The results showed that the glossiness of the specimens got worse and some cracks appeared on their surface during the course of ageing, the tensile strength and bending strengths of the specimens first increased and then decreased. The ILSS of the composites decreased after they were aged in the xenon arc lamp cell, but increased while they were aged in the thermo-oxidative cell. The changes of these trends become more obvious during ageing in the xenon arc lamp cell, so the main influencing factor leading to the failure of this material is UV irradiation.
基金This work was supported by the Major Science and Technology Program for Water Pollution Control and Treatment in China(Nos.2017ZX07202-001 and 2017ZX07202-004).
文摘Pharmaceuticals and personal care products(PPCPs)are a unique group of emerging and nonpersistent contaminants.In this study,27 PPCPs in various water samples were extracted by solid phase extraction(SPE),and determined by isotope dilution method using liquid chromatography coupled to tandem triple quadruple mass spectrometer(LC-MS/MS).A total of 27 isotopically labeled standards(ILSs)were applied to correct the concentration of PPCPs in spiked ultrapure water,drinking water,river,effluent and influent sewage.The corrected recoveries were 73%-122%with the relative standard deviation(RSD)<16%,except for acetaminophen.The matrix effect for all kinds of water samples was<22%and the method quantitation limits(MQLs)were 0.45-8.6 ng/L.The developed method was successfully applied on environmental water samples.The SPE extracts of spiked ultrapure water,drinking water,river and wastewater effluent were stored for 70 days,and the ILSscorrected recoveries of 27 PPCPs were obtained to evaluate the correction ability of ILSs in the presence of variety interferences.The recoveries of 27 PPCPs over 70 days were within the scope of 72%-140%with the recovery variation<37%in all cases.The isotope dilution method seems to be of benefit when the extract has to be stored for long time before the instrument analysis.
文摘It is well known that voids have detrimental effects on the performance of composites. This study aims to provide a practical method for predicting the effects of process induced voids on the properties of composites. Representative volume elements （RVE） for carbon fibre/epoxy composites of various fibre volume fractions and void contents are created, and the moduli and strengths are derived by finite element anal- ysis （FEA）. Regression models are fitted to the FEA data for predicting composite properties including tensile, compressive and shear. The strengths of composite laminates including tensile strngth and interlaminar shear strength （ILSS） are calculated with the aid of the developed models. The model predictions are compared with various experimental data and good agreement is found. The outcome from this study provides a useful optimisation and robust design tool for realising affordable composite prod- ucts when process induced voids are taken into account.
