Lunar impact glasses have been identified as crucial indicators of geochemical information regarding their source regions. Impact glasses can be categorized as either local or exotic. Those preserving geochemical sign...Lunar impact glasses have been identified as crucial indicators of geochemical information regarding their source regions. Impact glasses can be categorized as either local or exotic. Those preserving geochemical signatures matching local lithologies (e.g., mare basalts or their single minerals) or regolith bulk soil compositions are classified as “local”. Otherwise, they could be defined as “exotic”. The analysis of exotic glasses provides the opportunity to explore previously unsampled lunar areas. This study focuses on the identification of exotic glasses within the Chang’e-5 (CE-5) soil sample by analyzing the trace elements of 28 impact glasses with distinct major element compositions in comparison with the CE-5 bulk soil. However, the results indicate that 18 of the analyzed glasses exhibit trace element compositions comparable to those of the local CE-5 materials. In particular, some of them could match the local single mineral component in major and trace elements, suggesting a local origin. Therefore, it is recommended that the investigation be expanded from using major elements to including nonvolatile trace elements, with a view to enhancing our understanding on the provenance of lunar impact glasses. To achieve a more accurate identification of exotic glasses within the CE-5 soil sample, a novel classification plot of Mg# versus La is proposed. The remaining 10 glasses, which exhibit diverse trace element variations, were identified as exotic. A comparative analysis of their chemical characteristics with remote sensing data indicates that they may have originated from the Aristarchus, Mairan, Sharp, or Pythagoras craters. This study elucidates the classification and possible provenance of exotic materials within the CE-5 soil sample, thereby providing constraints for the enhanced identification of local and exotic components at the CE-5 landing site.展开更多
Low velocity impact experiments were carried out on E-glass/epoxy composite laminates having varying thicknesses at sub zero and elevated temperatures using hemi spherical steel impactor of 16 mm diameter with impact ...Low velocity impact experiments were carried out on E-glass/epoxy composite laminates having varying thicknesses at sub zero and elevated temperatures using hemi spherical steel impactor of 16 mm diameter with impact energies in the rage of 50-150 J.The performance of the laminates was assessed in terms of energy absorption,maximum displacement,peak force and failure behaviour.Results indicated that the effect of temperature on energy absorption of the laminate is negligible although the laminates are embrittling at sub zero temperatures.However it has influence on failure behaviour and displacement.Peak force has increased linearly with increase in laminate thickness from 5 to 10 mm.However it got reduced by 25% when temperature was increased from-20℃ to 100℃,Based on experimental results,laminate perforation energies were predicted using curve fitting equations.Statistical analysis was carried out using Taguchi method to identify the global effects of various parameters on laminate performance and confirmed that the laminate thickness has significant influence as compared to temperature,for the studied range.展开更多
The failure wave has been observed propagating in glass under impact loading since 1991. It is a continuous fracture zone which may be associated with the damage accumulation process during the propagation of shock wa...The failure wave has been observed propagating in glass under impact loading since 1991. It is a continuous fracture zone which may be associated with the damage accumulation process during the propagation of shock waves. A progressive fracture model was proposed to describe the failure wave formation and propagation in shocked glass considering its heterogeneous meso-structures. The original and. nucleated microcracks will expand along the pores and other defects with concomitant dilation when shock loading is below the Hugoniot Elastic Limit. The governing equation of the failure wave is characterized by inelastic bulk strain with material damage and fracture. And the inelastic bulk strain consists of dilatant strain from nucleation and expansion of microcracks and condensed strain from the collapse of the original pores. Numerical simulation of the free surface velocity was performed and found in good agreement with planar impact experiments on K9 glass at China Academy of Engineering Physics. And the longitudinal, lateral and shear stress histories upon the arrival of the failure wave were predicted, which present the diminished shear strength and lost spall strength in the failed layer.展开更多
Boro-silicate glass samples were coated with chemically treated multi-walled carbon nanotubes (MWCNTs) to study the resistance offered by the coatings under the high strain rate impact. Impact testing of these glass s...Boro-silicate glass samples were coated with chemically treated multi-walled carbon nanotubes (MWCNTs) to study the resistance offered by the coatings under the high strain rate impact. Impact testing of these glass samples was performed on Split Hopkinson Pressure Bar (SHPB), where strain rates were varied from 500/s to 3300/s. However, the comparisons were limited to samples subjected to a strain rate of 2300/s to 3000/s so that the effect of only variable deposits of coatings on the stress-strain behavior of glass can be studied. Variable deposits (0.1 mg to 0.8 mg) of MWCNTs were coated uniformly on glass samples having a disc shape with a fixed surface area (79 mm2) to observe the effect of the coating on the impact absorption capacity of glass. It was observed that the small thickness of about 25 μm formed due to the fact that 0.2 mg of MWCNTs deposit spread over the surface increased the impact absorption capacity of the glass pieces by nearly 70%. However, beyond this amount when the deposit was increased to 0.4 mg, the coating thickness got doubled to nearly 49 μm and this led to a fall in absorption capacity which remained static till 0.8 mg deposit. However, even this decrease in capacity was able to absorb 30% more impact than offered by pure glass sample.展开更多
In the present paper, the high velocity impact of 9 mm soft lead projectile on 10 mm and 30 mm thick Eglass/epoxy composites was studied using a 450 kV Flash X-ray radiography(FXR) system. The basic parameters of FXR ...In the present paper, the high velocity impact of 9 mm soft lead projectile on 10 mm and 30 mm thick Eglass/epoxy composites was studied using a 450 kV Flash X-ray radiography(FXR) system. The basic parameters of FXR imaging, such as effect of ratio of target to film(TF) and source to target(ST) distances and X-ray penetration thickness of the composite material were optimized based on clarity and the actual dimensions of the objects. The optimized parameters were used in the FXR imaging of the ballistic event of 9 mm soft projectile on E-glass/epoxy composite. The real time deformation patterns of both the projectile and composite target during the ballistic impact were captured and studied at different time intervals. The notable failure modes of the 10 mm thick target with time include fibre breakage, bulging on the back side, delamination, recovery of the bulging, reverse bulging and its recovery. However, with increase in thickness of the target to 30 mm the only failure mechanism observed is the breaking of fibres. The ballistic impact event was also numerically simulated using commercially available LS-DYNA software. The numerically simulated deformation patterns of the projectile and target at different time intervals are closely matching with the corresponding radiographic images.展开更多
为研究碳‑玻纤维混杂层合板在弹击作用下的损伤特征及其剩余承载性能,本文结合实验测试、无损检测与有限元模拟方法,对典型直升机桨叶混杂层合板在不同入射角条件下的弹击损伤形貌及剩余强度进行了系统研究。首先,通过90°与22.5...为研究碳‑玻纤维混杂层合板在弹击作用下的损伤特征及其剩余承载性能,本文结合实验测试、无损检测与有限元模拟方法,对典型直升机桨叶混杂层合板在不同入射角条件下的弹击损伤形貌及剩余强度进行了系统研究。首先,通过90°与22.5°两种入射角的弹击试验,结合(Computed tomography,CT)扫描技术分析了弹孔形貌及内部损伤分布规律。结果表明,入射角对弹击损伤形态及剩余拉伸承载能力具有显著影响,斜向入射条件下的真实内部损伤范围明显大于表面可视弹孔区域,试件的剩余拉伸强度整体降低且离散性增大。进一步建立了考虑弹孔几何与损伤分布特征的有限元模型,并通过用户子程序引入损伤因子(User‑defined material subroutine,UMAT)描述材料强度退化,实现了弹击后拉伸失效过程的数值模拟。有限元预测结果与实验结果总体误差控制在±15%以内,验证了模型在预测弹击后层合板剩余拉伸强度方面的有效性。相关研究可为直升机桨叶等关键复合材料结构在受弹击后的损伤评估与损伤容限设计提供参考。展开更多
The presence of glass microspherules enclosing relict grains, shattered quartz and silicon carbide in white sandstone beds near the Jurassic-Cretaceous boundary in west central Sinai indicates a cosmic impact event. C...The presence of glass microspherules enclosing relict grains, shattered quartz and silicon carbide in white sandstone beds near the Jurassic-Cretaceous boundary in west central Sinai indicates a cosmic impact event. Characterization of the impact microspherules and proposing a reasonable scenario for their origin are the aims of this work. Field observations, optical, binocular, scanning electron and high-resolution transmitted electron microscopy investigations and chemical analyses were carried out. The study revealed that glass microspherules have high Al<sub>2</sub>O<sub>3</sub> and FeO contents and low CaO and MgO contents. The high content of Al<sub>2</sub>O<sub>3</sub> indicates that the source of microtektite-like microspherules is attributed to the melting of a clay-rich sandstone and carbonaceous matter, while the high content of FeO indicates admixing with projectile matter. The reaction between silica and carbon was carried out under conditions of high temperature (T > 1000°C) and carbon (C/Si > 1) which resulted in the production of silicon carbide with microdiamond intergrowth. Consequently, this intergrowth is in accordance with the impact origin via rapid condensation and growth within a vapor phase. In spite of the fact that no source crater has been recognized to date in the study area, the authors propose at least a single cosmic impact event scenario for the recorded glass microspherules in west central Sinai. The impact excavated the Paleozoic siliciclastic sedimentary rocks and then the glass microspherules showered the area of study. The deposition of microtektite-like glass particles within the white sandstone beds of the Malha Formation took place in the fluvial plain terrestrial environment. This setting precluded severe post-depositional reworking, yielding preservation of the glass particles in a primary layer. Eventually, lateral migration of the braided channels led to the reworking of the microspherules layer and the spatial dispersal of the shattered quartz.展开更多
Transparent armor consists of glass-polymer laminates in most cases.The formation and propagation of damage in the different glass layers has a strong influence on the ballistic resistance of such laminates.In order t...Transparent armor consists of glass-polymer laminates in most cases.The formation and propagation of damage in the different glass layers has a strong influence on the ballistic resistance of such laminates.In order to clarify(he course of events during projectile penetration,an experimental technique was developed,which allows visualizing the onset and propagation of damage in each single layer of the laminate.A telecentric objective lens was used together with a microsecond video camera that allows recording 100 frames at a maximum rate of 1 MHz in a backlit photography set-up.With this technique,the damage evolution could be visualized in glass laminates consisting of four glass layers with lateral dimensions 500 mm x 500 mm.Damage evolution was recorded during penetration of 7.62 mm AP projectiles with tungsten carbide core and a total mass of 1 1.1 g in the impact velocity range from 800 to 880 m/s.In order to measure the deformation of single glass plates within the laminates,a piece of reflecting tape was attached to the corresponding glass plate,and photonic Doppler velocimetry(PDV) was applied.With the photonic Doppler velocimeter.an infrared laser is used to illuminate an object to be measured and the Doppler-shifted light is superimposed to a reference light beam at the detector.The simultaneous visualization and PDV measurement of the glass deformation allow determining the deformation at the time of the onset of fracture.The analysis of the experimental data was supported by numerical simulations,using the AUTODYN commercial hydro-code.展开更多
The work described herein consists of experimental measurement of the post-impact buckling loads of E- glass/epoxy laminates. Composite samples with stacking sequence of [+45/?45/90/0]2s were subjected to low-velocity...The work described herein consists of experimental measurement of the post-impact buckling loads of E- glass/epoxy laminates. Composite samples with stacking sequence of [+45/?45/90/0]2s were subjected to low-velocity impact loading at energy levels of 36, 56.13, 79.95, 110.31 and 144 J. The impact tests were conducted with a specially developed vertical drop weight testing machine. Impact parameters like peak load, absorbed energy, deflection at peak load and damage area were evaluated and compared. Damaged specimens were subjected to compressive axial forces and buckling loads of the specimens were obtained. The relation between energy levels and buckling loads is investigated.展开更多
The erosion resistance tests were used to research the erosion wear behavior of CaO-Al-2O-3-SiO-2 system glass-ceramic. With the orthogonal test method, the factors that affect the erosion wear of CaO-Al-2O-3-SiO-2 sy...The erosion resistance tests were used to research the erosion wear behavior of CaO-Al-2O-3-SiO-2 system glass-ceramic. With the orthogonal test method, the factors that affect the erosion wear of CaO-Al-2O-3-SiO-2 system glass-ceramic such as particles property, impact angle, impact time, size of particles were discussed.The results show that erosion rate rises along a straight line at the early period of erosion wear.With the impact time increased,the erosion rate deviates from original staight line,tendency of the erosion rate increases.With the size of paricle increased,it will have more kinetic energy,the erosion rate of the surface of glass-ceramics ploate rises.展开更多
Tensile impact experiments of EC8.0-24×7 glass fiber bundles atdifferent low tempera- tures T(14 deg. C, -40 deg. C and -100 deg. C)and strain rates ε were carried out, and complete stres-straincurves were obtai...Tensile impact experiments of EC8.0-24×7 glass fiber bundles atdifferent low tempera- tures T(14 deg. C, -40 deg. C and -100 deg. C)and strain rates ε were carried out, and complete stres-straincurves were obtained. Within the range of the experiment temperaturesand strain rates, it is found that the initial modulus E, theultimate strength σ_max and the unstable strain ε_b of the glassfiber bundles all increase with ε at an identical T. At an identicalε, with the decrease of T, E and σ_max increase; but ε_b increaseswhen 14 deg. C >T>-40 deg. C and decreases when -40 deg. C>T>-100deg. C.展开更多
To overcome the problem of interlaminar delamination of thermoplastic polyurethane laminated glass, silicate glass was etched with hydrofluoric acid and thermoplastic polyurethane was then treated with cold plasma. Co...To overcome the problem of interlaminar delamination of thermoplastic polyurethane laminated glass, silicate glass was etched with hydrofluoric acid and thermoplastic polyurethane was then treated with cold plasma. Compared with the untreated samples, the interlaminar shear strength of acid etching samples, cold plasma-treated samples and acid etching combined with cold plasma-treated samples increased by 97%, 84% and 341%, respectively. Acid etching combined with cold plasma-treated samples exhibited a higher flexural strength and strain as compared with the untreated samples. The impact energy of acid etching samples, cold plasmatreated samples and acid etching combined with cold plasma-treated samples increased by 8.7%, 8.1% and 11.6%, respectively, in comparison with the untreated samples. FT-IR analysis showed that a large number of -C-O, CO N and CO O C groups appeared on the surface of cold plasma-treated thermoplastic polyurethane, which resulted in the formation of hydrogen bonds. SEM results showed that some pittings formed on the surface of the silicate glass treated by acid etching, which resulted in the formation of a three-dimensional interface structure between tile silicate glass and polyurethane. Hydrogen bonds combined with the three-dimensional interface between silicate glass and polyurethanes co-improved the mechanical properties of thermoplastic polyurethanes laminated glass.展开更多
基金funded by the National Natural Science Foundation of China (Grant Nos. 42241103 and 62227901)the Key Research Program of the Institute of Geology and Geophysics, Chinese Academy of Sciences (Grant Nos. IGGCAS-202101 and IGGCAS-202401)
文摘Lunar impact glasses have been identified as crucial indicators of geochemical information regarding their source regions. Impact glasses can be categorized as either local or exotic. Those preserving geochemical signatures matching local lithologies (e.g., mare basalts or their single minerals) or regolith bulk soil compositions are classified as “local”. Otherwise, they could be defined as “exotic”. The analysis of exotic glasses provides the opportunity to explore previously unsampled lunar areas. This study focuses on the identification of exotic glasses within the Chang’e-5 (CE-5) soil sample by analyzing the trace elements of 28 impact glasses with distinct major element compositions in comparison with the CE-5 bulk soil. However, the results indicate that 18 of the analyzed glasses exhibit trace element compositions comparable to those of the local CE-5 materials. In particular, some of them could match the local single mineral component in major and trace elements, suggesting a local origin. Therefore, it is recommended that the investigation be expanded from using major elements to including nonvolatile trace elements, with a view to enhancing our understanding on the provenance of lunar impact glasses. To achieve a more accurate identification of exotic glasses within the CE-5 soil sample, a novel classification plot of Mg# versus La is proposed. The remaining 10 glasses, which exhibit diverse trace element variations, were identified as exotic. A comparative analysis of their chemical characteristics with remote sensing data indicates that they may have originated from the Aristarchus, Mairan, Sharp, or Pythagoras craters. This study elucidates the classification and possible provenance of exotic materials within the CE-5 soil sample, thereby providing constraints for the enhanced identification of local and exotic components at the CE-5 landing site.
文摘Low velocity impact experiments were carried out on E-glass/epoxy composite laminates having varying thicknesses at sub zero and elevated temperatures using hemi spherical steel impactor of 16 mm diameter with impact energies in the rage of 50-150 J.The performance of the laminates was assessed in terms of energy absorption,maximum displacement,peak force and failure behaviour.Results indicated that the effect of temperature on energy absorption of the laminate is negligible although the laminates are embrittling at sub zero temperatures.However it has influence on failure behaviour and displacement.Peak force has increased linearly with increase in laminate thickness from 5 to 10 mm.However it got reduced by 25% when temperature was increased from-20℃ to 100℃,Based on experimental results,laminate perforation energies were predicted using curve fitting equations.Statistical analysis was carried out using Taguchi method to identify the global effects of various parameters on laminate performance and confirmed that the laminate thickness has significant influence as compared to temperature,for the studied range.
基金Project supported by the National Natural Science Foundation of China (Nos.10272047 and 10376046).
文摘The failure wave has been observed propagating in glass under impact loading since 1991. It is a continuous fracture zone which may be associated with the damage accumulation process during the propagation of shock waves. A progressive fracture model was proposed to describe the failure wave formation and propagation in shocked glass considering its heterogeneous meso-structures. The original and. nucleated microcracks will expand along the pores and other defects with concomitant dilation when shock loading is below the Hugoniot Elastic Limit. The governing equation of the failure wave is characterized by inelastic bulk strain with material damage and fracture. And the inelastic bulk strain consists of dilatant strain from nucleation and expansion of microcracks and condensed strain from the collapse of the original pores. Numerical simulation of the free surface velocity was performed and found in good agreement with planar impact experiments on K9 glass at China Academy of Engineering Physics. And the longitudinal, lateral and shear stress histories upon the arrival of the failure wave were predicted, which present the diminished shear strength and lost spall strength in the failed layer.
文摘Boro-silicate glass samples were coated with chemically treated multi-walled carbon nanotubes (MWCNTs) to study the resistance offered by the coatings under the high strain rate impact. Impact testing of these glass samples was performed on Split Hopkinson Pressure Bar (SHPB), where strain rates were varied from 500/s to 3300/s. However, the comparisons were limited to samples subjected to a strain rate of 2300/s to 3000/s so that the effect of only variable deposits of coatings on the stress-strain behavior of glass can be studied. Variable deposits (0.1 mg to 0.8 mg) of MWCNTs were coated uniformly on glass samples having a disc shape with a fixed surface area (79 mm2) to observe the effect of the coating on the impact absorption capacity of glass. It was observed that the small thickness of about 25 μm formed due to the fact that 0.2 mg of MWCNTs deposit spread over the surface increased the impact absorption capacity of the glass pieces by nearly 70%. However, beyond this amount when the deposit was increased to 0.4 mg, the coating thickness got doubled to nearly 49 μm and this led to a fall in absorption capacity which remained static till 0.8 mg deposit. However, even this decrease in capacity was able to absorb 30% more impact than offered by pure glass sample.
文摘In the present paper, the high velocity impact of 9 mm soft lead projectile on 10 mm and 30 mm thick Eglass/epoxy composites was studied using a 450 kV Flash X-ray radiography(FXR) system. The basic parameters of FXR imaging, such as effect of ratio of target to film(TF) and source to target(ST) distances and X-ray penetration thickness of the composite material were optimized based on clarity and the actual dimensions of the objects. The optimized parameters were used in the FXR imaging of the ballistic event of 9 mm soft projectile on E-glass/epoxy composite. The real time deformation patterns of both the projectile and composite target during the ballistic impact were captured and studied at different time intervals. The notable failure modes of the 10 mm thick target with time include fibre breakage, bulging on the back side, delamination, recovery of the bulging, reverse bulging and its recovery. However, with increase in thickness of the target to 30 mm the only failure mechanism observed is the breaking of fibres. The ballistic impact event was also numerically simulated using commercially available LS-DYNA software. The numerically simulated deformation patterns of the projectile and target at different time intervals are closely matching with the corresponding radiographic images.
文摘为研究碳‑玻纤维混杂层合板在弹击作用下的损伤特征及其剩余承载性能,本文结合实验测试、无损检测与有限元模拟方法,对典型直升机桨叶混杂层合板在不同入射角条件下的弹击损伤形貌及剩余强度进行了系统研究。首先,通过90°与22.5°两种入射角的弹击试验,结合(Computed tomography,CT)扫描技术分析了弹孔形貌及内部损伤分布规律。结果表明,入射角对弹击损伤形态及剩余拉伸承载能力具有显著影响,斜向入射条件下的真实内部损伤范围明显大于表面可视弹孔区域,试件的剩余拉伸强度整体降低且离散性增大。进一步建立了考虑弹孔几何与损伤分布特征的有限元模型,并通过用户子程序引入损伤因子(User‑defined material subroutine,UMAT)描述材料强度退化,实现了弹击后拉伸失效过程的数值模拟。有限元预测结果与实验结果总体误差控制在±15%以内,验证了模型在预测弹击后层合板剩余拉伸强度方面的有效性。相关研究可为直升机桨叶等关键复合材料结构在受弹击后的损伤评估与损伤容限设计提供参考。
文摘The presence of glass microspherules enclosing relict grains, shattered quartz and silicon carbide in white sandstone beds near the Jurassic-Cretaceous boundary in west central Sinai indicates a cosmic impact event. Characterization of the impact microspherules and proposing a reasonable scenario for their origin are the aims of this work. Field observations, optical, binocular, scanning electron and high-resolution transmitted electron microscopy investigations and chemical analyses were carried out. The study revealed that glass microspherules have high Al<sub>2</sub>O<sub>3</sub> and FeO contents and low CaO and MgO contents. The high content of Al<sub>2</sub>O<sub>3</sub> indicates that the source of microtektite-like microspherules is attributed to the melting of a clay-rich sandstone and carbonaceous matter, while the high content of FeO indicates admixing with projectile matter. The reaction between silica and carbon was carried out under conditions of high temperature (T > 1000°C) and carbon (C/Si > 1) which resulted in the production of silicon carbide with microdiamond intergrowth. Consequently, this intergrowth is in accordance with the impact origin via rapid condensation and growth within a vapor phase. In spite of the fact that no source crater has been recognized to date in the study area, the authors propose at least a single cosmic impact event scenario for the recorded glass microspherules in west central Sinai. The impact excavated the Paleozoic siliciclastic sedimentary rocks and then the glass microspherules showered the area of study. The deposition of microtektite-like glass particles within the white sandstone beds of the Malha Formation took place in the fluvial plain terrestrial environment. This setting precluded severe post-depositional reworking, yielding preservation of the glass particles in a primary layer. Eventually, lateral migration of the braided channels led to the reworking of the microspherules layer and the spatial dispersal of the shattered quartz.
文摘Transparent armor consists of glass-polymer laminates in most cases.The formation and propagation of damage in the different glass layers has a strong influence on the ballistic resistance of such laminates.In order to clarify(he course of events during projectile penetration,an experimental technique was developed,which allows visualizing the onset and propagation of damage in each single layer of the laminate.A telecentric objective lens was used together with a microsecond video camera that allows recording 100 frames at a maximum rate of 1 MHz in a backlit photography set-up.With this technique,the damage evolution could be visualized in glass laminates consisting of four glass layers with lateral dimensions 500 mm x 500 mm.Damage evolution was recorded during penetration of 7.62 mm AP projectiles with tungsten carbide core and a total mass of 1 1.1 g in the impact velocity range from 800 to 880 m/s.In order to measure the deformation of single glass plates within the laminates,a piece of reflecting tape was attached to the corresponding glass plate,and photonic Doppler velocimetry(PDV) was applied.With the photonic Doppler velocimeter.an infrared laser is used to illuminate an object to be measured and the Doppler-shifted light is superimposed to a reference light beam at the detector.The simultaneous visualization and PDV measurement of the glass deformation allow determining the deformation at the time of the onset of fracture.The analysis of the experimental data was supported by numerical simulations,using the AUTODYN commercial hydro-code.
文摘The work described herein consists of experimental measurement of the post-impact buckling loads of E- glass/epoxy laminates. Composite samples with stacking sequence of [+45/?45/90/0]2s were subjected to low-velocity impact loading at energy levels of 36, 56.13, 79.95, 110.31 and 144 J. The impact tests were conducted with a specially developed vertical drop weight testing machine. Impact parameters like peak load, absorbed energy, deflection at peak load and damage area were evaluated and compared. Damaged specimens were subjected to compressive axial forces and buckling loads of the specimens were obtained. The relation between energy levels and buckling loads is investigated.
基金FundedbytheNaturalScienceFoundationofHubeiProv ince (2 0 0 2AB0 77)
文摘The erosion resistance tests were used to research the erosion wear behavior of CaO-Al-2O-3-SiO-2 system glass-ceramic. With the orthogonal test method, the factors that affect the erosion wear of CaO-Al-2O-3-SiO-2 system glass-ceramic such as particles property, impact angle, impact time, size of particles were discussed.The results show that erosion rate rises along a straight line at the early period of erosion wear.With the impact time increased,the erosion rate deviates from original staight line,tendency of the erosion rate increases.With the size of paricle increased,it will have more kinetic energy,the erosion rate of the surface of glass-ceramics ploate rises.
基金the National Natural Science Foundation of China(No.19772058)
文摘Tensile impact experiments of EC8.0-24×7 glass fiber bundles atdifferent low tempera- tures T(14 deg. C, -40 deg. C and -100 deg. C)and strain rates ε were carried out, and complete stres-straincurves were obtained. Within the range of the experiment temperaturesand strain rates, it is found that the initial modulus E, theultimate strength σ_max and the unstable strain ε_b of the glassfiber bundles all increase with ε at an identical T. At an identicalε, with the decrease of T, E and σ_max increase; but ε_b increaseswhen 14 deg. C >T>-40 deg. C and decreases when -40 deg. C>T>-100deg. C.
基金supported by Aeronautical Science Foundation of China(Nos.2012ZF56025,2011ZF56013)the Scientific Research Project Foundation of Jiangxi Provincial Education Department(Nos.GJJ11497,GJJ13477)State Key Laboratory of Advanced Technology for Materials Synthesis and Processing of China(Wuhan University of Technology)(No.2012-KF-8)
文摘To overcome the problem of interlaminar delamination of thermoplastic polyurethane laminated glass, silicate glass was etched with hydrofluoric acid and thermoplastic polyurethane was then treated with cold plasma. Compared with the untreated samples, the interlaminar shear strength of acid etching samples, cold plasma-treated samples and acid etching combined with cold plasma-treated samples increased by 97%, 84% and 341%, respectively. Acid etching combined with cold plasma-treated samples exhibited a higher flexural strength and strain as compared with the untreated samples. The impact energy of acid etching samples, cold plasmatreated samples and acid etching combined with cold plasma-treated samples increased by 8.7%, 8.1% and 11.6%, respectively, in comparison with the untreated samples. FT-IR analysis showed that a large number of -C-O, CO N and CO O C groups appeared on the surface of cold plasma-treated thermoplastic polyurethane, which resulted in the formation of hydrogen bonds. SEM results showed that some pittings formed on the surface of the silicate glass treated by acid etching, which resulted in the formation of a three-dimensional interface structure between tile silicate glass and polyurethane. Hydrogen bonds combined with the three-dimensional interface between silicate glass and polyurethanes co-improved the mechanical properties of thermoplastic polyurethanes laminated glass.
