Advanced Materials Research Vols. 452-453

Abstract: The present paper proposes a novel cableless magnetic actuator that exhibits a very high thrusting force and is capable of high speed locomotion in a thin pipe by using new type propulsion module. The magnetic actuator is moved according to the vibration amplitude and elastic energy of a mass-spring system due to mechanical resonance energy. The proposed actuator contains an electrical inverter that directly transforms DC from button batteries into AC. The electrical DC-AC inverter incorporates a mass-spring system, a reed switch and a curved permanent magnet that switches under an electromagnetic force. Experimental results indicate that the proposed actuator is able to move upward at a speed of 51 mm/s by the power provided by 8 button batteries when pulling a 10 g load mass. This cableless magnetic actuator has several possible applications, including small pipe inspection and maintenance.

Abstract: Edge drop is an important quality evaluating index for strip cross-section with the increasing of requirement for higher gauge accuracy to meet customer's demand. The mathematical model of roll shifting system plays an important role in controlling the edge drop on modern tandem cold rolling mills. Based on the explicit dynamic finite element method, a 3D finite element simulation model of rolls and strip is established for a large ultra-wide 6-high cold rolling mill with the developed EDW (edge drop control work roll) and the matched CVC intermediate roll to investigate the effect of work roll shift on edge drop of strip. Considering on the characteristics of EDW work rolls, equivalent area compensated method has been put forward to build the shifting model for edge drop control. The results indicated that the values of edge drop are less than 7μm by using the proper shifting model and the shifting model can be used to guide the practical production.

Abstract: In web winding process, the effects of speed-up and speed-down on internal stresses of wound roll have been investigated. The air-entrainment can be obtained theoretically using the modified nonlinear Hakiel model. In this research work, air-entrainment model established by Hamrock and Dowson was applied to estimate the initial air film layers into a wound roll in the winding system with a nip-roller. Moreover, the characteristics of a wound roll were examined under varying tension and varying speed conditions. The numerical results showed the radial stress, tangential stress, and friction force distributions at central inside a wound roll under the condition for a wound roll without wrinkle and slippage phenomena.

Abstract: Created HTM50200 shaped stone processing center’s virtual model Based on VERICUT and UG software, in accordance with the actual parameter, configuration component tree, and machine tool library, and system parameter of the machine, and simulate the processing program. On the exists of interference, collision, had cut, and owed cut, modify the errors, analysis the surface quality, if it don’t meet the processing precision requirements program the region again, make it eventually reach the requirements standard. According the cutter, physical properties of work materials to calculate the optimal cutting parameters, make the program optimize on the feed rate and spindle speed. In the practical application of simulation technology and manufacturing processes, reduce the risks in traditional test cutting process and personnel's labor intensity, save the machines’ take up time, improve the efficiency of use.

Abstract: No-tillage planting is one of the most important assignments of the conservation tillage technology. The 2BMF-9 wheat no-tillage planter was taken as object，the planting experiment on field were carried out on eight kinds of surface treatments, then various performance indices, emergence of seeding rate and tiller number were obtained on each surface treatment. The grey correlation analyzing concluded that the seeding uniformity, covering soil ability and passing ability had greatly influenced the emergence of seeding rate and tiller number. Eight kinds of surface treatments were categorized with the principle of gray clustering evaluation.

Abstract: The present paper is concerned with the study of compressible flow in a converging-diverging nozzle. From a theoretical and experimental investigation of the flow in an illustrative channel with convergent-divergent area variation, the behavior of the flow along the channel was found to be generally similar in trend to the flow in a stationary convergent-divergent nozzle. In compressible flows, the density and temperature variations are often significant. Therefore, the following study provides additional information on shock location, Mach number behavior and pressure distribution by varying nozzle length. The obtained curves show pressure distribution and Mach number along the two dimensioned nozzles which enable us to compare the experimental data with the theoretical calculations. Furthermore, interesting graphs are plotted which show the relationship between some nozzle parameters and flow characteristics.

Abstract: In this paper, transition probability analysis for piezoceramic actuators is presented. Nonlinear constitutive equations and resulting system models quantifying the non-linear and hysteretic field-displacement relations inherent to piezoceramic elements are developed. In the model development, lattice-level energy relations are combined with stochastic homogenization techniques to construct non-linear constitutive relations which accommodate the piezoceramic hysteresis. Simulation results demonstrated the effectiveness of the theoretical model development using transition probability analysis.

Abstract: This paper presents the effects of a sudden load change and sudden speed change on the performance characteristics of two surfaces under elliptical contact with elastohydrodynamic lubrication. The non-Newtonian lubricant for the research work are modeled based on Carreau viscosity model. The time dependent modified Reynolds equation and elastic equation were formulated for compressible fluid. Perturbation method, Newton Raphson method and full adaptive multigrid method were implemented and solved to obtain the film pressure, film thickness profiles and friction coefficient in the contact regime at various applied loads and speeds. Simulation results show the friction coefficient increase significantly under sudden loads. The minimum film thickness and friction coefficient both decrease significantly as speed is decreased.

Abstract: Through analysis of the dynamics process of hydraulic rock drill, this paper builds a model of the impact mechanism of hydraulic rock drill with AMESim software, obtains curves of the displacements of the piston and valve core, and gets the pressure of the piston chamber. The dynamic analysis of the results indicates that the model of the impact mechanism of hydraulic rock drill agrees well with the principle of hydraulic rock drill. As a result, this research provides a new theoretical basis and method for the hydraulic rock drill.

Abstract: Real time Monitoring system is an important gurantee for the water quality. SDI-12 water sensors are used to monitor the water conductivity, temperature, dissolved oxygen, Ph, turbidity and other parameters in this paper. The signal of the wastewater is collected to the ARM chip, and then it is processed by the chip. The preliminary result will be displayed on a handheld terminal in real time. The handheld terminal also integrates the function of remote data transmission, which can transmit the original water data to a central server for storage via GPRS. Central server analyse the wastewater data based on ontology. Meanwhile, the system can also control water detector via remote control, which realizes the unattended effect.