使用共固化成型工艺制备了含碳纤复合材料约束层的轻质约束阻尼结构,采用180°剥离强度测试、振动性能测试对结构界面结合强度、减振性能进行测试,并通过扫描电镜观测试样内部界面微观形貌。结果表明,所制备碳纤复合约束阻尼结构中...使用共固化成型工艺制备了含碳纤复合材料约束层的轻质约束阻尼结构,采用180°剥离强度测试、振动性能测试对结构界面结合强度、减振性能进行测试,并通过扫描电镜观测试样内部界面微观形貌。结果表明,所制备碳纤复合约束阻尼结构中约束层与阻尼层界面结合紧密,剥离强度接近5 k N/m,减振量超过19d B,结构减重50%以上,具备较高的应用价值。展开更多
Carbon fiber reinforced polyamide 12(CF/PA12),a new material renowned for its excellent mechanical and thermal properties,has drawn significant industry attention.Using the steady-state research to heat transfer,a ser...Carbon fiber reinforced polyamide 12(CF/PA12),a new material renowned for its excellent mechanical and thermal properties,has drawn significant industry attention.Using the steady-state research to heat transfer,a series of simulations to investigate the heat transfer properties of CF/PA12 were conducted in this study.Firstly,by building two-and three-dimensional models,the effects of the porosity,carbon fiber content,and arrangement on the heat transfer of CF/PA12 were examined.A validation of the simulation model was carried out and the findings were consistent with those of the experiment.Then,the simulation results using the above models showed that within the volume fraction from 0% to 28%,the thermal conductivity of CF/PA12 increased greatly from 0.0242 W/(m·K)to 10.8848 W/(m·K).The increasing porosity had little influence on heat transfer characteristic of CF/PA12.The direction of the carbon fiber arrangement affects the heat transfer impact,and optimal outcomes were achieved when the heat flow direction was parallel to the carbon fiber.This research contributes to improving the production methods and broadening the application scenarios of composite materials.展开更多
Carbon fiber-reinforced polymer(CFRP)is widely used in aerospace applications.This kind of material may face the threat of high-velocity impact in the process of dedicated service,and the relevant research mainly cons...Carbon fiber-reinforced polymer(CFRP)is widely used in aerospace applications.This kind of material may face the threat of high-velocity impact in the process of dedicated service,and the relevant research mainly considers the impact resistance of the material,and lacks the high-velocity impact damage monitoring research of CFRP.To solve this problem,a real high-velocity impact damage experiment and structural health monitoring(SHM)method of CFRP plate based on piezoelectric guided wave is proposed.The results show that CFRP has obvious perforation damage and fiber breakage when high-velocity impact occurs.It is also proved that guided wave SHM technology can be effectively used in the monitoring of such damage,and the damage can be reflected by quantifying the signal changes and damage index(DI).It provides a reference for further research on guided wave structure monitoring of high/hyper-velocity impact damage of CFRP.展开更多
Carbon fiber reinforced aluminum matrix (Cf/Al) composite has many excellent properties, and it has received more and more attention. Two-dimensional (2D) Cf/Al composites were fabricated by vacuum and pressure in...Carbon fiber reinforced aluminum matrix (Cf/Al) composite has many excellent properties, and it has received more and more attention. Two-dimensional (2D) Cf/Al composites were fabricated by vacuum and pressure infiltration, which was an integrated technique and could provide high vacuum and high infiltration pressure. The effect of specific pressure on the infiltration quality of the obtained composites was comparatively evaluated through microstructure observation. The experimental results show that satisfied Cf/Al composites could be fabricated at the specific pressure of 75 MPa. In this case, the preform was infiltrated much more completely by aluminum alloy liquid, and the residual porosity was seldom found. It is found that the ultimate tensile strength of the obtained Cf/Al composite reached maximum at the specific pressure of 75 MPa, which was improved by 138.9% compared with that of matrix alloy.展开更多
A dynamic measuring apparatus was developed to investigate the infiltration process of liquid metal into the fibrous preform. 10% (volume fraction) chopped carbon fiber preforms were infiltrated with magnesium alloy...A dynamic measuring apparatus was developed to investigate the infiltration process of liquid metal into the fibrous preform. 10% (volume fraction) chopped carbon fiber preforms were infiltrated with magnesium alloy under different infiltration pressures. The threshold pressure and flow behavior of liquid metal infiltrating into the preforms were calculated and measured. The microstructure of obtained Ct4Mg composites was observed. The results indicate that the measured threshold pressure for infiltration was 0.048 MPa, which was larger than the calculated value. The infiltration rate increased with the increase of infiltration pressure, but the increase amplitude decreased gradually. The tiny pores in the composites could be eliminated by increasing the infiltration pressure. When the infiltration pressure rose to 0.6 MPa, high quality C1/Mg composite was obtained.展开更多
To study the response characteristics of the carbon fiber fabric reinforced composites under impact loading, one dimensional strain impact test, multi gauge technique and Lagrange analysis method are used. The decay...To study the response characteristics of the carbon fiber fabric reinforced composites under impact loading, one dimensional strain impact test, multi gauge technique and Lagrange analysis method are used. The decaying rule of the stress σ , strain ε , strain rate ε · and density ρ with time and space is obtained. By the theory of dynamics, the impact response characteristics of the material is analyzed and discussed.展开更多
文摘使用共固化成型工艺制备了含碳纤复合材料约束层的轻质约束阻尼结构,采用180°剥离强度测试、振动性能测试对结构界面结合强度、减振性能进行测试,并通过扫描电镜观测试样内部界面微观形貌。结果表明,所制备碳纤复合约束阻尼结构中约束层与阻尼层界面结合紧密,剥离强度接近5 k N/m,减振量超过19d B,结构减重50%以上,具备较高的应用价值。
基金Projects(52206216,52376085)supported by the National Natural Science Foundation of ChinaProject(2023JJ40744)supported by the Natural Science Foundation of Hunan Province,China。
文摘Carbon fiber reinforced polyamide 12(CF/PA12),a new material renowned for its excellent mechanical and thermal properties,has drawn significant industry attention.Using the steady-state research to heat transfer,a series of simulations to investigate the heat transfer properties of CF/PA12 were conducted in this study.Firstly,by building two-and three-dimensional models,the effects of the porosity,carbon fiber content,and arrangement on the heat transfer of CF/PA12 were examined.A validation of the simulation model was carried out and the findings were consistent with those of the experiment.Then,the simulation results using the above models showed that within the volume fraction from 0% to 28%,the thermal conductivity of CF/PA12 increased greatly from 0.0242 W/(m·K)to 10.8848 W/(m·K).The increasing porosity had little influence on heat transfer characteristic of CF/PA12.The direction of the carbon fiber arrangement affects the heat transfer impact,and optimal outcomes were achieved when the heat flow direction was parallel to the carbon fiber.This research contributes to improving the production methods and broadening the application scenarios of composite materials.
基金supported by the National Natural Science Foundation of China(Nos.51921003,52275153)the Fundamental Research Funds for the Central Universities(No.NI2023001)+2 种基金the Research Fund of State Key Laboratory of Mechanics and Control for Aero-space Structures(No.MCAS-I-0423G01)the Fund of Pro-spective Layout of Scientific Research for Nanjing University of Aeronautics and Astronauticsthe Priority Academic Program Development of Jiangsu Higher Education Institu-tions of China.
文摘Carbon fiber-reinforced polymer(CFRP)is widely used in aerospace applications.This kind of material may face the threat of high-velocity impact in the process of dedicated service,and the relevant research mainly considers the impact resistance of the material,and lacks the high-velocity impact damage monitoring research of CFRP.To solve this problem,a real high-velocity impact damage experiment and structural health monitoring(SHM)method of CFRP plate based on piezoelectric guided wave is proposed.The results show that CFRP has obvious perforation damage and fiber breakage when high-velocity impact occurs.It is also proved that guided wave SHM technology can be effectively used in the monitoring of such damage,and the damage can be reflected by quantifying the signal changes and damage index(DI).It provides a reference for further research on guided wave structure monitoring of high/hyper-velocity impact damage of CFRP.
基金Projects(51221001,51275417)supported by the National Natural Science Foundation of ChinaProject(SKLSP201103)supported by the Fund of the State Key Laboratory of Solidification ProcessingProject(B08040)supported by the Introducing Talents of Discipline toUniversities,China
文摘Carbon fiber reinforced aluminum matrix (Cf/Al) composite has many excellent properties, and it has received more and more attention. Two-dimensional (2D) Cf/Al composites were fabricated by vacuum and pressure infiltration, which was an integrated technique and could provide high vacuum and high infiltration pressure. The effect of specific pressure on the infiltration quality of the obtained composites was comparatively evaluated through microstructure observation. The experimental results show that satisfied Cf/Al composites could be fabricated at the specific pressure of 75 MPa. In this case, the preform was infiltrated much more completely by aluminum alloy liquid, and the residual porosity was seldom found. It is found that the ultimate tensile strength of the obtained Cf/Al composite reached maximum at the specific pressure of 75 MPa, which was improved by 138.9% compared with that of matrix alloy.
基金Projects(51221001,51275417)supported by the National Natural Science Foundation of ChinaProject(2013AA8011004B)supported by National High Technology Research and Development Program of ChinaProject(CX201011)supported by the Doctorate Foundation of Northwestern Polytechnical University,China
文摘A dynamic measuring apparatus was developed to investigate the infiltration process of liquid metal into the fibrous preform. 10% (volume fraction) chopped carbon fiber preforms were infiltrated with magnesium alloy under different infiltration pressures. The threshold pressure and flow behavior of liquid metal infiltrating into the preforms were calculated and measured. The microstructure of obtained Ct4Mg composites was observed. The results indicate that the measured threshold pressure for infiltration was 0.048 MPa, which was larger than the calculated value. The infiltration rate increased with the increase of infiltration pressure, but the increase amplitude decreased gradually. The tiny pores in the composites could be eliminated by increasing the infiltration pressure. When the infiltration pressure rose to 0.6 MPa, high quality C1/Mg composite was obtained.
文摘To study the response characteristics of the carbon fiber fabric reinforced composites under impact loading, one dimensional strain impact test, multi gauge technique and Lagrange analysis method are used. The decaying rule of the stress σ , strain ε , strain rate ε · and density ρ with time and space is obtained. By the theory of dynamics, the impact response characteristics of the material is analyzed and discussed.