Applied Mechanics and Materials Vols. 37-38

Abstract: The BP ANN was established based on MATLAB to simulate the supercritical CO₂ extraction process for extracting peanut oil. The supercritical CO₂ extraction experiment for peanut oil was carried out and the experimental results were used to train the BP ANN. The operating pressure, temperature and time were regarded as the inputs of the BP ANN and the percentage extraction as the output. By testing the BP ANN with other groups of experimental data, the precision of the BP ANN was verified. This BP ANN can predict the percentage extraction when the processing parameters of supercritical CO₂ extraction are given, and the optimization of the processing parameters can also be realized.

Abstract: The numerical simulation of temperature field of Q235 steel in 700 mm×700 mm mold has been carried out by software Fluent to assess the effect of the structure of the immersed nozzle on the heat flow transfer and solidification of the molten steel, which shows that the best result can be achieved when the nozzle with the five- side- holes was immersed in the depth of 150 mm and its opening angle is 15°.

Abstract: The mechanical behaviors of prototype and simulated model of reinforced concrete aqueduct with multi-longitudinal beams were analyzed by 3D FEM. The regularity of structural deformation and concrete stress of the aqueducts were studied, what influenced by the surface force instead of dead weight and the equivalent concentrated load or ladder load instead of lateral water load. The rationality of the loading method for aqueduct model test is evaluated. It shows that the ladder surface pressure is superior to concentrated loads to simulate the lateral water load, and the equivalent dead loads can be added reasonably to simulate the additional self-weight of model.

Abstract: To improve the energy-regenerative efficiency and robustness of electric vehicle (EV), a novel energy-regenerative controller was designed and applied to the charge current loop of the EV. The controller that combines neural network (NN) with traditional sliding mode controller (SMC) comprises a radial basis function NN (RBFNN) and a SMC. The RBFNN is used to adaptively adjust the switching gain of the SMC. The simulation model of the energy-regenerative system is built with MATLAB/SIMULINK, and the simulation results show that comparing with traditional SMC, the NNSMC has better performance at response speed, steady-state tracking error and resisting disturbance in energy-regenerative process. Additionally, it can recover more energy.

Abstract: Finite element model was established for the special-section ring rolling. The whole process of ring rolling was simulated based on the DEFORM software. The law that the rolling force is influenced by the idle roll feed speed and main roll rotational speed were found. The results show that the roughcast structure should be similar to finished product structure. IT is significant to optimize roughcast structure and processing parameter, and to improve efficiency of rolling.

Abstract: A new hydraulic drawing system of coal mining machine is proposed in this paper. The variable plunger pump adopted in the hydraulic drawing system of coal mining machine is replaced by load-sensing variable displacement pump. The working principle and energy-saving of the new system are introduced. The performance of the new system is obtained by the simulation study using AMESim.

Abstract: Based on the up to date development of the ultrasonic machining (USM) technology, applications and development trends of the ultrasonic machining tool are described. Automatic control including intelligent control and adaptive control, also tools in processing as an attachment and load matching system are trends in ultrasonic machining tool. The latest applications of ultrasonic machining technology in deep hole machining, ultrasonic elliptical vibration cutting, ultrasonic grinding, ultrasonic milling and ultrasonic combined machining are summarized, processing accuracy and processing efficiency have got a lot of progress. The development trends and future prospect of the ultrasonic machining technology are expounded. Studying the ultrasonic cutting mechanism, ultrasonic combined machining technology and micro-ultrasonic machining technology are the trends of ultrasonic machining.

Abstract: A finite element method is used to simulate the sixth drawing process of nickel coating battery shells. The material’s mechanical parameters are tested and shown and the forming tool parameters are given. The Belytschko-Wong-Chiang shell elements are used and the kinematical work hardening model is adopted for the sheets. The stress-strain field in the components in the forming processes is obtained. The nickel coating yielded at the drawing process, the effective plastic strain reached 0.3769-0.7524. The coated sheet does not delaminate in the bonding interface during the deformation process. This study can aid the production of coating battery shells.

Abstract: With the development of economy and society, more and more energy is needed to meet the requirement of industries and social life. It is necessary to find new types of energy that is clear, high effective and non-polluted. Although wet etching is widely used in industries to prepare the silicon surface texture, the etching process is stochastic and the influence light is trapping. Many efforts have been made, such as adjusting the proportion of different acids, to improve the quality of silicon surface by wet etching, the effectiveness is still limited. In this paper, a new approach is presented to prepare the surface texturing. By combining wet etching and ultrasonic vibration, the sodium or acid molecular motion can be controlled, and the pyramid structure in silicon surface can be made regular.

Abstract: An unconstrained optimization model, applicable to radial deviation measurement, is established for assessing cylindricity errors by the minimum circumscribed cylinder evaluation. The properties of the objective function in the optimization model are thoroughly investigated. On the basis of the modern theory of convex functions, it is strictly proved that the objective function is a continuous and non-differentiable and convex function defined on the four-dimensional Euclidean space R4. Therefore, the minimal value of the objective function is unique and any of its minimal point must be its global minimal point. Thus, any existing optimization algorithm, so long as it is convergent, can be used to solve the objective function to get the wanted values of cylindricity errors by the minimum circumscribed cylinder assessment. An example is given to verify the theoretical results presented.