The effect of vinyltrimethoxysilane(VTMS)graft and SiO_(2) on the structure and mechanical properties of silane-grafted-polyethylene/SiO_(2)(VTMS-g-PE/SiO_(2))nanocomposite fibers and ropes was studied.Scanning electr...The effect of vinyltrimethoxysilane(VTMS)graft and SiO_(2) on the structure and mechanical properties of silane-grafted-polyethylene/SiO_(2)(VTMS-g-PE/SiO_(2))nanocomposite fibers and ropes was studied.Scanning electron microscopy(SEM),Fourier transfer infrared(FT-IR),differential scanning calorimetry analysis(DSC)and tensile mechanical tests were performed to characterize the morphology,thermal and mechanical properties of nanocomposite fibers and ropes.The results revealed that the SiO_(2) nanoparticles were well dispersed throughout the polymeric matrix.With increasing SiO_(2) content,T_(m),the melt peak width and X_(c),degree of crystallinity,of VTMS-g-PE/SiO_(2) nanocomposite fibers increased.The breaking load and breaking strength of the nanocomposite fiber ropes were remarkably improved compared to pure PE fiber ropes and elongation at break was also decreased.展开更多
We studied consecutive impact loading on woven high-modulus polyethylene rope, which is used in robotics fields. An impact tester was developed to conduct the experiments. Five consecutive impact loads (five drops) we...We studied consecutive impact loading on woven high-modulus polyethylene rope, which is used in robotics fields. An impact tester was developed to conduct the experiments. Five consecutive impact loads (five drops) were applied to the rope and the stiffness of the loading part that corresponds to each drop was evaluated. The stiffness of the woven ropes was affected strongly by consecutive impact loading. The change in stiffness is undesirable in some applications such as in robotic fields. Therefore, we have proposed a method that can optimize changes in stiffness by applying a preload before impact testing (preload treatment). The experimental results show that preload is an efficient way to reduce changing rope stiffness. We have also proposed an empirical equation that can estimate the rope stiffness after arbitrary preload treatment, and this equation is a function of the number of drops and the static preload level. The equation can be used to determine the preload treatment conditions to stabilize the stiffness of the woven ropes before they are used in engineering fields.展开更多
Spiral fibers were considered to be an ideal toughening phase of ultra-high torsional release effect.In this work,ZrB_(2)(Z)-20 vol%SiC(S)spiral fiber(ZS_(sf))with controllable structure was prepared by a combination ...Spiral fibers were considered to be an ideal toughening phase of ultra-high torsional release effect.In this work,ZrB_(2)(Z)-20 vol%SiC(S)spiral fiber(ZS_(sf))with controllable structure was prepared by a combination approach of liquid rope effect and non-solvent-induced phase separation.Dominantly depended on the kinematic viscosity(η),dropping height(H),and flow rate(Q),the geometric parameters of ZS_(sf) involving filament diameter(d)and coil diameter(D)were followed the relationship of d≈0.516×10^(-3) Q^(1/2)H^(−1/4) and D≈0.25×10^(-3)(Q/H)^(1/3),respectively,within the optimizedηof 10-15 Pa·s.Three different microstructures of ZS_(sf) were achieved by adjusting the polymer/solvent/non-solvent system assisted with phase diagram calculation,including dense,hollow,and hierarchical pore structures.The ZrB_(2)-SiC with 1 wt%ZS_(sf) composites prepared by hot isostatic pressing(HIP)exhibited a~30%increase in fracture toughness(KIC,4.41 MPa·m^(1/2))compared with the ZrB_(2)-SiC composite,where the microscopic fracture toughness of the ZS_(sf) was~80%higher than that of the matrix.The fibers with a~10 nm in-situ-synthesized graphite phase amongst grain boundaries of ZrB_(2) and SiC changed the fracture mode,and promoted the crack deflection and pull-out adjacent the interface of matrix and the fiber.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.31502213)Special Scientific Research Funds for Central Non-profit Institutes(East China Sea Fisheries Research Institute)(Grant No.2015T01)the National Key Technology R&D Program(Grant No.2013BAD13B02).
文摘The effect of vinyltrimethoxysilane(VTMS)graft and SiO_(2) on the structure and mechanical properties of silane-grafted-polyethylene/SiO_(2)(VTMS-g-PE/SiO_(2))nanocomposite fibers and ropes was studied.Scanning electron microscopy(SEM),Fourier transfer infrared(FT-IR),differential scanning calorimetry analysis(DSC)and tensile mechanical tests were performed to characterize the morphology,thermal and mechanical properties of nanocomposite fibers and ropes.The results revealed that the SiO_(2) nanoparticles were well dispersed throughout the polymeric matrix.With increasing SiO_(2) content,T_(m),the melt peak width and X_(c),degree of crystallinity,of VTMS-g-PE/SiO_(2) nanocomposite fibers increased.The breaking load and breaking strength of the nanocomposite fiber ropes were remarkably improved compared to pure PE fiber ropes and elongation at break was also decreased.
文摘We studied consecutive impact loading on woven high-modulus polyethylene rope, which is used in robotics fields. An impact tester was developed to conduct the experiments. Five consecutive impact loads (five drops) were applied to the rope and the stiffness of the loading part that corresponds to each drop was evaluated. The stiffness of the woven ropes was affected strongly by consecutive impact loading. The change in stiffness is undesirable in some applications such as in robotic fields. Therefore, we have proposed a method that can optimize changes in stiffness by applying a preload before impact testing (preload treatment). The experimental results show that preload is an efficient way to reduce changing rope stiffness. We have also proposed an empirical equation that can estimate the rope stiffness after arbitrary preload treatment, and this equation is a function of the number of drops and the static preload level. The equation can be used to determine the preload treatment conditions to stabilize the stiffness of the woven ropes before they are used in engineering fields.
基金supported by the Science and Technology Innovation Program of Shanghai in 2020 (Grant No.STCSM-20520714300)the National Natural Science Foundation of China (Grant No.U19A2099)+1 种基金National Major Science and Technology Projects of China (Grant No.J2019-VIII-0003-0165)Open Project of Shanghai Key Laboratory of Spacecraft Mechanism.
文摘Spiral fibers were considered to be an ideal toughening phase of ultra-high torsional release effect.In this work,ZrB_(2)(Z)-20 vol%SiC(S)spiral fiber(ZS_(sf))with controllable structure was prepared by a combination approach of liquid rope effect and non-solvent-induced phase separation.Dominantly depended on the kinematic viscosity(η),dropping height(H),and flow rate(Q),the geometric parameters of ZS_(sf) involving filament diameter(d)and coil diameter(D)were followed the relationship of d≈0.516×10^(-3) Q^(1/2)H^(−1/4) and D≈0.25×10^(-3)(Q/H)^(1/3),respectively,within the optimizedηof 10-15 Pa·s.Three different microstructures of ZS_(sf) were achieved by adjusting the polymer/solvent/non-solvent system assisted with phase diagram calculation,including dense,hollow,and hierarchical pore structures.The ZrB_(2)-SiC with 1 wt%ZS_(sf) composites prepared by hot isostatic pressing(HIP)exhibited a~30%increase in fracture toughness(KIC,4.41 MPa·m^(1/2))compared with the ZrB_(2)-SiC composite,where the microscopic fracture toughness of the ZS_(sf) was~80%higher than that of the matrix.The fibers with a~10 nm in-situ-synthesized graphite phase amongst grain boundaries of ZrB_(2) and SiC changed the fracture mode,and promoted the crack deflection and pull-out adjacent the interface of matrix and the fiber.
