Advanced Materials Research Vol. 510

Abstract: The article takes the blower as the research object, uses MATLAB software, extracts the typical fault eigenvalue of blower based on Wavelet Packet Analysis theory, according to the diagnosis mode energy decides fault degree. Establishes the link of MATLAB and database, which is convenient for storing and processing the fault eigenvalue. Forecast and predict the trend of blowers typical fault effectively through the application of the Grey prediction theory. Predicted results are very close to measured data, which proves the methods validity.

Abstract: Embedded giant magnetostrictive actuator (EGMA) is one of the most important applications of magnetostrictive material. Giant magnetostrictive actuators can deliver big-output displacement and can be driven at high frequencies. These characteristics make them suitable for a variety of positioning. However, because of the limitation of structure, the drive coil and EGMA cannot be any size as needed, so how to maximize the displacement in the limitative situation by optimization becomes the key of design. Several methods are available in the literature, but the coupling drive magnetic field of EGMA and its matrix material is often ignored. In fact, there was a close relationship between the matrix material and the distribution of drive magnetic field. To analyze the relationship, this paper establishes the magnetic circuit model for EGMA. The simulation of the coupling drive magnetic field is also presented. Finally the assumption is validated through experimental tests carried out with two different matrix materials.

Abstract: When induction motor is directly driven by PWM power converter, high-frequency common-mode current will be generated inside the motor due to the high-frequency common-mode voltage load. So in this paper, on the basis of the analysis of the coupling effect of the parasitic elements on high-frequency current which include elements between induction motor windings, between the winding and the stator and between the winding and the rotor, According to the structural characteristics of the motor, it is obtained that the parasitic element between the first turns of the stator winding coil and ground can provide low impedance flow path for high frequency common mode current, most of the high-frequency common mode current drain into ground through this path, and the motor stator winding has the uniform transmission line characteristics. The correctness of the conclusions is verified by the experimental results of two different induction motor.

Abstract: Based on the rod reconfigurable design idea, by changing the lever's shape and position, and tandem combination, we can create all kinds of force-magnifying institutions to meet different job requires. In this paper, use pneumatic muscle as drive component combined with reconfigurable rod institutions, fixture system has been innovated,the working principle of the fixture system are introduced, its calculating formulae of output power are also given. The fixture system adapted to the development of the greening trend, has broad application.

Abstract: Based on the forming technology of "hollow laser beam and internal powder, adopting a novel device with coaxial inside-beam and internal powder feeding, the accumulation experiments of the change-diametral rotary parts are carried out on the substrate of 45# steel. This study is focused on the control of the parts inclination angle, Z axis incremental and laser power on the forming characteristics of the parts. The results show that with the Coaxial Inside-beam Powder Feeding Accumulation, the quality of molding parts that this experiment gets finally is higher with smooth appearance and lower roughness. The grain is fine and the microstructure distribute uniformly from bottom to top of forming parts.

Abstract: Feed servo system is an important part in CNC machine tool. In order to promote CNC machine tools precision, it is particularly important to enhance the control methods research on feed servo system. In this paper, different mathematical models of CNC machine tools feed servo system in different control modes are established, and their transfer functions are obtained, also the corresponding simulation models are constructed by using Simulink tools under MATLAB environment. Through simulating, the relationship between the systems parameters and the performance of servo system are obtained, some reliable theoretical basis can be achieved for improving and enhancing CNC machine tool servo system performance. Therefore some references for the performance optimization of feed servo system in CNC machine tool are provided.

Abstract: Dynamic analysis software ANSYS/LS-DYNA is applied to fluid-structure coupling simulation analysis of cartridge valve. Transient mechanical properties of cartridge valve and impact characteristics of interaction between hydraulic oil and valve spool in depressurization process were got. The result of study showed that the stability of depressurization process is related to the contacting time between valve spool and valve sleeve. The squeezing time of hydraulic oil is best not more than 0.01s. The peak impact time of hydraulic oil to valve spool in steady depressurization process is 140kN. And the maximum VonMises between valve spool and valve sleeve is 456MPa.

Abstract: The finite element software was used to get the X-cor sandwich’s shear strength. During the shear strength analysis, the failure criterion and materials stiffness degradation rules fitting for the analysis of X-cor sandwich’s failure mechanism were proposed and the X-cor sandwich’s failure process and modes were also clarified. According to the failure criterion we used the elements with stiffness degradation and their distributions in the finite element model to simulate the types and propagation path of the failure and the failure mechanisms of X-cor sandwich under shear were explained. The finite element analysis indicates during the shear firstly the resin regions fail and then the multiple failure modes of Z-pin pull-out from the face-sheet, Z-pin shear off and Z-pin buckling all exist. The propagation paths of the failure elements are dispersive. By contrasting the finite element results and test results the values are consistent well and the error range is -10.4%~7.4%. The comparison results show that the failure criterion and stiffness degradation rules are reasonable and this method can be used to predict the X-cor sandwich’s shear strength.

Abstract: Pulleys and bushing have different linear expansion coefficient, relatively sliding may occur between them when hated, therefore, we have to ensure that there's enough interference volume within pulleys and bushing. First of all, using simplify numerical method calculated theoretical extreme temperature, then taking simulate analysis with ABAQUS finite element analysis software, through the change of CPRESS and COPEN in different temperature field, extract the extremely working temperature of aluminum pulleys. and then determined the limitation and cooperation relationships by comparison.

Abstract: Two kinds of methods for the control of the gap between pressing tool head and support in CNC incremental forming have been discussed (i.e. pressing path adjustment method and support shape adjustment method), and whose effects on forming accuracy are analyzed by using the Finite Element Analyses. The methods for the generation of pressing paths and supports have been given for the two forming method of the pressing path adjustment and support shape adjustment, and the Finite Element Analysis models have been built for them respectively. The method of digital simulations for the two forming cases mentioned above based on the ANSYS/LS-DYNA software has been presented and the forming precision of the two forming methods are analyzed through the comparison of digital simulation results.