A novel steel–carbon fibre/polyetheretherketone(CF/PEEK)hybrid shaft is proposed,considering the thermal stability,negative coefficient of thermal expansion in fibre orientation,and high stiffness of CF/PEEK,which is...A novel steel–carbon fibre/polyetheretherketone(CF/PEEK)hybrid shaft is proposed,considering the thermal stability,negative coefficient of thermal expansion in fibre orientation,and high stiffness of CF/PEEK,which is expected to suppress the thermal deformation of shafts.A laser-assisted in-situ consolidation(LAC)process,together with its equipment,was developed to manufacture the hybrid shaft.Firstly,the optimal process parameters,including the laser-heated temperature and placement speed,were investigated.A maximum short-beam shear strength of 80.7 MPa was achieved when the laser-heated temperature was 500°C and the placement speed was 100 mm/s.In addition,the failure modes and the effect of environmental temperature on the CF/PEEK samples were analyzed.Both interlayer cracks and inelastic deformation failure modes were observed.The formation and propagation of cracks were further investigated through digital image correlation(DIC).Furthermore,internal defects of the CF/PEEK sample were detected using X-ray tomography scans,and a minimum porosity of 0.23%was achieved with the optimal process parameters.Finally,two steel–CF/PEEK hybrid shafts,with different fibre orientations,were manufactured based on the optimal process parameters.The surface temperature distributions and thermal deformations were investigated using a self-established deformation/temperature measurement platform.The hybrid shaft showed an 85.7%reduction in radial displacement with hoop fibre orientation and an 11.5%reduction in axial displacement with cross fibre orientation compared with the steel shaft.The results indicate that the proposed method has great potential to improve the thermal stability of hybrid shafts and the accuracy of machine tools.展开更多
In-situ consolidation forming of high-performance thermoplastic composites by Automated Fiber Placement(AFP)is of significant interest in aerospace.During the laying process,the heating temperature has a great influen...In-situ consolidation forming of high-performance thermoplastic composites by Automated Fiber Placement(AFP)is of significant interest in aerospace.During the laying process,the heating temperature has a great influence on the quality of the formed components.A threedimensional heat transfer finite element model of Carbon Fiber(CF)/Polyether Ether Ketone(PEEK)heated by Slit Structure Nozzle Hot Gas Torch(SSNHGT)assisted AFP is proposed.The influence of gas flow rate,heat transfer distance,and laying speed on heating temperature is analysed.The results show that the overall temperature increases and then decreases as the gas flow rate increases.With the increase in heat transfer distance and laying speed,the overall temperature decreases.Meanwhile,the gas flow rate has the greatest influence on the temperature of CF/PEEK being heated,followed by the laying speed and finally the heat transfer distance.Furthermore,the model can also be extended to other fiber-reinforced polymer composites formed by hot gas torch assisted AFP,which can guide the optimization of process parameters for subsequent heating temperature control.展开更多
基金supported by the National Nature Science Foundation of China(No.52175440)the Aeronautics Science Foundation of China(No.2023Z049076001)+3 种基金the Science and Technology Innovation Fund of Shanghai Aerospace(No.SAST2022-058)the Open Fund of State Key Laboratory of Mechanical Transmissions(No.SKLMT-MSKFKT-202202)the Key R&D Program of Zhejiang Province(No.2023C01058)the Experimental Technique Project of Zhejiang University(No.SYBJS202302),China.
文摘A novel steel–carbon fibre/polyetheretherketone(CF/PEEK)hybrid shaft is proposed,considering the thermal stability,negative coefficient of thermal expansion in fibre orientation,and high stiffness of CF/PEEK,which is expected to suppress the thermal deformation of shafts.A laser-assisted in-situ consolidation(LAC)process,together with its equipment,was developed to manufacture the hybrid shaft.Firstly,the optimal process parameters,including the laser-heated temperature and placement speed,were investigated.A maximum short-beam shear strength of 80.7 MPa was achieved when the laser-heated temperature was 500°C and the placement speed was 100 mm/s.In addition,the failure modes and the effect of environmental temperature on the CF/PEEK samples were analyzed.Both interlayer cracks and inelastic deformation failure modes were observed.The formation and propagation of cracks were further investigated through digital image correlation(DIC).Furthermore,internal defects of the CF/PEEK sample were detected using X-ray tomography scans,and a minimum porosity of 0.23%was achieved with the optimal process parameters.Finally,two steel–CF/PEEK hybrid shafts,with different fibre orientations,were manufactured based on the optimal process parameters.The surface temperature distributions and thermal deformations were investigated using a self-established deformation/temperature measurement platform.The hybrid shaft showed an 85.7%reduction in radial displacement with hoop fibre orientation and an 11.5%reduction in axial displacement with cross fibre orientation compared with the steel shaft.The results indicate that the proposed method has great potential to improve the thermal stability of hybrid shafts and the accuracy of machine tools.
基金co-supported by the National Natural Science Foundation of China(No.52205460)the Heilongjiang Provincial Natural Science Foundation of China(No.LH2023E041)the China Scholarship Council(CSC)to study abroad at the Nanyang Technological University.
文摘In-situ consolidation forming of high-performance thermoplastic composites by Automated Fiber Placement(AFP)is of significant interest in aerospace.During the laying process,the heating temperature has a great influence on the quality of the formed components.A threedimensional heat transfer finite element model of Carbon Fiber(CF)/Polyether Ether Ketone(PEEK)heated by Slit Structure Nozzle Hot Gas Torch(SSNHGT)assisted AFP is proposed.The influence of gas flow rate,heat transfer distance,and laying speed on heating temperature is analysed.The results show that the overall temperature increases and then decreases as the gas flow rate increases.With the increase in heat transfer distance and laying speed,the overall temperature decreases.Meanwhile,the gas flow rate has the greatest influence on the temperature of CF/PEEK being heated,followed by the laying speed and finally the heat transfer distance.Furthermore,the model can also be extended to other fiber-reinforced polymer composites formed by hot gas torch assisted AFP,which can guide the optimization of process parameters for subsequent heating temperature control.
