Based on the dynamics of ABS-equipped vehicles during cornering braking, the electronic brake- force distribution （EBD） control methods of ABS-equipped vehicles during cornering braking are proposed. According to th...Based on the dynamics of ABS-equipped vehicles during cornering braking, the electronic brake- force distribution （EBD） control methods of ABS-equipped vehicles during cornering braking are proposed. According to the dynamics and the tire model under tire adhesion limit, the stability acceptance criteria of vehicles during cornering braking are proposed. According to the stability acceptance criteria and the ABS control, the EBD control methods of ABS-equipped vehicles during cornering braking are implemented by adjusting the threshold values of tires slip independently. The vehicle states during cornering braking at two typical initial velocities of the vehicle are analyzed by the EBD control methods, whose results indicate the EBD control methods can improve the braking performances of the vehicle during cornering braking comparing with the ABS control.展开更多
To optimize milling force and machining accuracy quality in corner milling process, the changing law of milling force is revealed by Finite Element Method（FEM）. Based on DEFORM software a serial of 3D FEM models for...To optimize milling force and machining accuracy quality in corner milling process, the changing law of milling force is revealed by Finite Element Method（FEM）. Based on DEFORM software a serial of 3D FEM models for corner milling process are devloped. Tool curved trajectory is achieved by establishing accurate relationship of tool location with milling time. Adaptive remeshing technique and iterative algorithm are adopted to ensure convergence of FEM model. Component force characteristics are revealed by analyzing FEM simulation results. It indicates that the milling force in Y direction becomes negative comparing with forces in X and Z direction. Magnitude of forces in three directions decreases with increase of spindle speed, while it increases with increase of milling feedrate. The simulation results for cutting force are in good agreement with those obtained from experiment. The FEM simulation model is first successfully established for corner milling process in this study, and the results provide a guide for optimizing cutting parameters in cutting process.展开更多
This work examines the physical effect of the edge-induced acoustic radiation force and torque on an acoustically radiating infinitely-long circular cylindrical source,located near a rigid corner.Assuming harmonic(lin...This work examines the physical effect of the edge-induced acoustic radiation force and torque on an acoustically radiating infinitely-long circular cylindrical source,located near a rigid corner.Assuming harmonic(linear)radiating waves of the source,vibrating in monopole or dipole radiation modes near a rigid corner-space in a non-viscous fluid,the modal series expansion method in cylindrical coordinates,the classical method of images and the translational addition theorem are applied to obtain the mathematical expressions for the radiation force and torque components in exact partial-wave series.Computational results illustrate the theory,and examine some of the conditions where the radiation force and torque components vanish,which has the potential to achieve total motion suppression(i.e.,translation or rotation).Furthermore,depending on the size parameter of the source and the distances from the rigid corner space,these physical observables take positive or negative values,anticipating the prediction of pulling/pushing motions toward the corner space,and possible spinning of the source clockwise or counter-clockwise.The present analysis and its results may be useful in some applications related to underwater acoustical oceanographic engineering of submerged objects,cloaking and stealth technology development and the experimental design of elongated unmanned autonomous vehicles or submarines,as well as the manipulation of an active carrier or ultrasound contrast agents of elongated cylindrical shapes near a corner space or chamber walls at a right angle.展开更多
基金the National Natural Science Foundation of China (50122155)
文摘Based on the dynamics of ABS-equipped vehicles during cornering braking, the electronic brake- force distribution （EBD） control methods of ABS-equipped vehicles during cornering braking are proposed. According to the dynamics and the tire model under tire adhesion limit, the stability acceptance criteria of vehicles during cornering braking are proposed. According to the stability acceptance criteria and the ABS control, the EBD control methods of ABS-equipped vehicles during cornering braking are implemented by adjusting the threshold values of tires slip independently. The vehicle states during cornering braking at two typical initial velocities of the vehicle are analyzed by the EBD control methods, whose results indicate the EBD control methods can improve the braking performances of the vehicle during cornering braking comparing with the ABS control.
基金Supported by National Natural Science Foundation of China(Grant Nos.51575147,51235003)Science Funds for the Young Innovative Talents of Harbin University of Science and Technology,China(Grant No.201507)
文摘To optimize milling force and machining accuracy quality in corner milling process, the changing law of milling force is revealed by Finite Element Method（FEM）. Based on DEFORM software a serial of 3D FEM models for corner milling process are devloped. Tool curved trajectory is achieved by establishing accurate relationship of tool location with milling time. Adaptive remeshing technique and iterative algorithm are adopted to ensure convergence of FEM model. Component force characteristics are revealed by analyzing FEM simulation results. It indicates that the milling force in Y direction becomes negative comparing with forces in X and Z direction. Magnitude of forces in three directions decreases with increase of spindle speed, while it increases with increase of milling feedrate. The simulation results for cutting force are in good agreement with those obtained from experiment. The FEM simulation model is first successfully established for corner milling process in this study, and the results provide a guide for optimizing cutting parameters in cutting process.
文摘This work examines the physical effect of the edge-induced acoustic radiation force and torque on an acoustically radiating infinitely-long circular cylindrical source,located near a rigid corner.Assuming harmonic(linear)radiating waves of the source,vibrating in monopole or dipole radiation modes near a rigid corner-space in a non-viscous fluid,the modal series expansion method in cylindrical coordinates,the classical method of images and the translational addition theorem are applied to obtain the mathematical expressions for the radiation force and torque components in exact partial-wave series.Computational results illustrate the theory,and examine some of the conditions where the radiation force and torque components vanish,which has the potential to achieve total motion suppression(i.e.,translation or rotation).Furthermore,depending on the size parameter of the source and the distances from the rigid corner space,these physical observables take positive or negative values,anticipating the prediction of pulling/pushing motions toward the corner space,and possible spinning of the source clockwise or counter-clockwise.The present analysis and its results may be useful in some applications related to underwater acoustical oceanographic engineering of submerged objects,cloaking and stealth technology development and the experimental design of elongated unmanned autonomous vehicles or submarines,as well as the manipulation of an active carrier or ultrasound contrast agents of elongated cylindrical shapes near a corner space or chamber walls at a right angle.
