Harmonic thermoelastic waves in helical strands with Maxwell–Cattaneo heat conduction areinvestigated analytically and numerically. The corresponding dispersion relation is a sixth-orderalgebraic equation, governed b...Harmonic thermoelastic waves in helical strands with Maxwell–Cattaneo heat conduction areinvestigated analytically and numerically. The corresponding dispersion relation is a sixth-orderalgebraic equation, governed by six non-dimensional parameters: two thermoelastic couplingconstants, one chirality parameter, the ratio between extensional and torsional moduli, the Fouriernumber, and the dimensionless thermal relaxation. The behavior of the solutions is discussedfrom two perspectives with an asymptotic-numerical approach: (1) the effect of thermal relaxationon the elastic wave celerities, and (2) the effect of thermoelastic coupling on the thermal wavecelerities. With small wavenumbers, the adiabatic solution for Fourier helical strands is recovered.However, with large wavenumbers, the solutions behave differently depending on the thermalrelaxation and chirality. Due to thermoelastic coupling, the thermal wave celerity deviates from theclassical result of the speed of second sound.展开更多
According to the requirement of automatization of drainpipe deposit cleaning work in the municipal engineering works,a kind of robot for drainpipe deposit cleaning work has been researched and manufactured with the si...According to the requirement of automatization of drainpipe deposit cleaning work in the municipal engineering works,a kind of robot for drainpipe deposit cleaning work has been researched and manufactured with the simulation analysis and the technique of virtual prototyping.In this paper,the composition principle and key techniques of the robot are elaborated in detail,including the technique of adapting and adjusting the change of pipe diameter,technique of obstacle crossing,technique of walking and driving and so on.The manufactured prototype and results of tests show that the robot possesses characteristics,such as adapting range of pipe diameter between 400 and 500 mm,the walk speed with 2 m /min,the drag force beyond 3 kN,and the walk distance with 1 km.展开更多
The market of stainless electric steel kettles is growing significantly, but the main mechanism for polishing kettles via traditional handwork operations limits the growth of electric kettle manufacturing. Based on th...The market of stainless electric steel kettles is growing significantly, but the main mechanism for polishing kettles via traditional handwork operations limits the growth of electric kettle manufacturing. Based on the successful multi-tool automatic polishing system for electric stainless steel kettles, regression analysis and orthogonal tests were employed to construct a polishing process model, with a purpose to improve the automatic polishing technology for electric stainless steel kettles. The model reveals the relationship between the surface roughness and processing parameters including gringding depth, abrasive tangent speed, workpiece rotating speed and axial feeding speed. Simulation and experimental results are in agreement,which shows that this modeling method is feasible in practice, and it can also be used as a guidance for planning automatic polishing process of electric stainless-steel kettles.展开更多
基金supported by the National Science Foundation of United States (Grants IIP-1362146 and CMMI-1462749)
文摘Harmonic thermoelastic waves in helical strands with Maxwell–Cattaneo heat conduction areinvestigated analytically and numerically. The corresponding dispersion relation is a sixth-orderalgebraic equation, governed by six non-dimensional parameters: two thermoelastic couplingconstants, one chirality parameter, the ratio between extensional and torsional moduli, the Fouriernumber, and the dimensionless thermal relaxation. The behavior of the solutions is discussedfrom two perspectives with an asymptotic-numerical approach: (1) the effect of thermal relaxationon the elastic wave celerities, and (2) the effect of thermoelastic coupling on the thermal wavecelerities. With small wavenumbers, the adiabatic solution for Fourier helical strands is recovered.However, with large wavenumbers, the solutions behave differently depending on the thermalrelaxation and chirality. Due to thermoelastic coupling, the thermal wave celerity deviates from theclassical result of the speed of second sound.
基金Sponsored by Heilongjiang Province,Department of Science and Technology,Major Science and Technology Projects (Grant No. GZ08A501)
文摘According to the requirement of automatization of drainpipe deposit cleaning work in the municipal engineering works,a kind of robot for drainpipe deposit cleaning work has been researched and manufactured with the simulation analysis and the technique of virtual prototyping.In this paper,the composition principle and key techniques of the robot are elaborated in detail,including the technique of adapting and adjusting the change of pipe diameter,technique of obstacle crossing,technique of walking and driving and so on.The manufactured prototype and results of tests show that the robot possesses characteristics,such as adapting range of pipe diameter between 400 and 500 mm,the walk speed with 2 m /min,the drag force beyond 3 kN,and the walk distance with 1 km.
文摘The market of stainless electric steel kettles is growing significantly, but the main mechanism for polishing kettles via traditional handwork operations limits the growth of electric kettle manufacturing. Based on the successful multi-tool automatic polishing system for electric stainless steel kettles, regression analysis and orthogonal tests were employed to construct a polishing process model, with a purpose to improve the automatic polishing technology for electric stainless steel kettles. The model reveals the relationship between the surface roughness and processing parameters including gringding depth, abrasive tangent speed, workpiece rotating speed and axial feeding speed. Simulation and experimental results are in agreement,which shows that this modeling method is feasible in practice, and it can also be used as a guidance for planning automatic polishing process of electric stainless-steel kettles.
