This study reports the investigations for repair of thermoplastic based automotive bumpers and bars with modified friction stir welding(MFSW)process.For MFSW,consumable tool of polyamide6(PA6)composite has been used f...This study reports the investigations for repair of thermoplastic based automotive bumpers and bars with modified friction stir welding(MFSW)process.For MFSW,consumable tool of polyamide6(PA6)composite has been used for joining of acrylonitrile butadiene styrene(ABS)composites.The dissimilar thermoplastics were processed for maintaining a useful range of melt flow properties followed by preparation of feed stock filament for fused deposition modeling(FDM)process through screw extrusion.Finally,3D printed PA6 based consumable rapid tool(RT)was prepared for MFSW.The joints prepared were subjected to flexural,hardness,morphological and thermal testing.The study has suggested the that maximum mechanical strength was obtained for sample welded at 1400 r/min,50 mm/min transverse speed and 3 mm plunge depth,whereas the minimum mechanical strength was obtained for sample welded at 1000 r/min,30 mm/min transverse speed and 2 mm plunge depth.The results are also supported with thermal analysis and photomicrographs.展开更多
This paper studies the global fixed time synchronization of complex dynamical network,including non-identical nodes with disturbances and uncertainties as well as input nonlinearity.First,a novel fixed time sliding ma...This paper studies the global fixed time synchronization of complex dynamical network,including non-identical nodes with disturbances and uncertainties as well as input nonlinearity.First,a novel fixed time sliding manifold is constructed to achieve the fixed time synchronization of complex dynamical network with disturbances and uncertainties.Second,a novel sliding mode controller is proposed to realize the global fixed time reachability of sliding surfaces.The outstanding feature of the designed control is that the fixed convergence time of both reaching and sliding modes can be adjusted to the desired values in advance by choosing the explicit parameters in the controller,which does not rest upon the initial conditions and the topology of the network.Finally,the effectiveness and validity of the obtained results are demonstrated by corresponding numerical simulations.展开更多
文摘This study reports the investigations for repair of thermoplastic based automotive bumpers and bars with modified friction stir welding(MFSW)process.For MFSW,consumable tool of polyamide6(PA6)composite has been used for joining of acrylonitrile butadiene styrene(ABS)composites.The dissimilar thermoplastics were processed for maintaining a useful range of melt flow properties followed by preparation of feed stock filament for fused deposition modeling(FDM)process through screw extrusion.Finally,3D printed PA6 based consumable rapid tool(RT)was prepared for MFSW.The joints prepared were subjected to flexural,hardness,morphological and thermal testing.The study has suggested the that maximum mechanical strength was obtained for sample welded at 1400 r/min,50 mm/min transverse speed and 3 mm plunge depth,whereas the minimum mechanical strength was obtained for sample welded at 1000 r/min,30 mm/min transverse speed and 2 mm plunge depth.The results are also supported with thermal analysis and photomicrographs.
文摘This paper studies the global fixed time synchronization of complex dynamical network,including non-identical nodes with disturbances and uncertainties as well as input nonlinearity.First,a novel fixed time sliding manifold is constructed to achieve the fixed time synchronization of complex dynamical network with disturbances and uncertainties.Second,a novel sliding mode controller is proposed to realize the global fixed time reachability of sliding surfaces.The outstanding feature of the designed control is that the fixed convergence time of both reaching and sliding modes can be adjusted to the desired values in advance by choosing the explicit parameters in the controller,which does not rest upon the initial conditions and the topology of the network.Finally,the effectiveness and validity of the obtained results are demonstrated by corresponding numerical simulations.
