Advanced Materials Research Vol. 852

Abstract: To improve the forging quality and avoid longitudinal cracks on forging surface, critical hole expansion ratio of ductile failure of metallic materials micromechanics was adopted as the criterion to judge whether crack occurs during upsetting, and the upsetting FEA model of 5CrNiMo hot die steel was established based on FEM software DEFORM-3D. The dangerous points on forging surface which crack may occur easily were analyzed based on the calculating results of the metal hole expansion ratio, and the influence of forgings shape on upsetting cracks were researched. The results show that when the relative reduction of the center point on the forgings surface exceeds 65%, the first crack occurs during upsetting; the shape coefficient can be used as the conditions and basis for cracks forecast by establishing the comparison expression between shape coefficient and hole expansion ratio during upsetting.

Abstract: Taking the remote controller back shell for example, the flow process of the injection molding including filling, packing, holding and cooling was simulated by using the process technology of Moldflow software, the best gate location and the information of weld lines, trapped gas, fill time, pressure and temperature were analyzed. At the same time, the product defects during the injection was predicted, the cause of defects and influence factors was analyzed, the mould design parameters were adjusted, the design of the mould was optimized. It realized mass production of the product.

Abstract: At present, crankshafts with larger size are finished mostly by abrasive cloth and manual steel brush, which is not ideal on finishing quality, efficiency and cost, especially cleanness degree does not meet design and use request. So horizontal spindle barrel finishing has been developed and has good finishing effects for crankshafts with small size. But this process has bad uniformity for connecting rod journal of crankshafts with larger size by simulation experiments. Aimed at the size, shape and weight of crankshafts with larger size, theoretic research is done, and main factors for finishing uniformity are analyzed. Finally its finishing project is defined and experiments are done. The research indicates that this process is very effective for crankshafts with larger size, and has also positive influence on efficiency and auto product line.

Abstract: In this article, an improved procedure based on ISO 5660-1 and ASTM E1474 was developed to ensure the effectiveness and reliability of cone calorimeter test of textile fabrics. In order to improve the instability for some easy shrinking fabrics exposed under heat in cone calorimeter test, an iron wire grid was applied to cover the top surface of polypropylene nonwovens and polyester fabrics to avoid drastic distortion caused by heating irritation. Results showed that the iron wire grid could avoid the distortion of the easy shrinking samples and stable test process, also success probability and results repeatability were also improved. A guiding effect was found during the test caused by the grid, which leaded to a better uniformity of polymer melt under the thermal or even on fire.

Abstract: In this paper, the GAMBIT of 3D model was adopted to divide the labyrinth gap in an unstructured approach. Simulation was carried out on one of the important factors which affect the labyrinth seal performance---the seal clearance. The results were compared with the simulation data of the 2D model. The experimental results prove that the effects of the circumferential turbulence make energy dissipation of the sealed cavity exacerbated; the throttling effect of the sealed cavity is significant and it plays a role that cannot be ignored in changing the labyrinth seal performance.

Abstract: The one-room and four-room tanks were modeled by finite element method to deeply research on the liquid-structure coupling problem in tanks. As the different constraint conditions, the analysis cases were formulated based on the orthogonal test method, to study the system's modality. The results show that, the frequency of one-room tank decreases with the increase of filling liquid when vertically fixed. When the one-room tank is fixed like a cantilever, there also is a descend trend of frequency, but in the case of liquid filling ratio 0.20, the frequency is abnormally increased with a minor rate 0.86%. Due to the different location, when filling ratio is 0.4, the frequency of cantilever system is 10.88% higher than that of vertical system. As for the four-room tank, the frequency is also nonlinear, and the lowest frequency is 40.47Hz, which is 82.81% lower than that of vertical system in the same filling ratio.

Abstract: This paper designs the contingency plan subsystems main function of cognition, tabletop derive, drill and data maintenance. Then it analyses the key technologies which include the construction of 3D scene, scene optimization, scene special efficiency, network communication and synchronization, and diffusion analysis of dangerous chemicals.

Abstract: The finite element computational package COMSOL multiphysics were used to simulate a bar plate dc discharge in argon at atmospheric pressure. The basic plasma properties such as electron density, ion density, metastable atom density, electron temperature, electric voltage and electric field were studied. The current-voltage (I-V) characteristic of numerical model is in good agreement well with experimental data. This model is simple and insightful as a theoretical tool for argon atmospheric pressure discharges.

Abstract: The steady-state thermal analysis models are established based on the thermal analysis of the Electric connectors. With the consideration to the internal heat conduction and the convection cooling, the three-dimensional solid model is imposed by the reasonable loads and boundary conditions and analyzed by ANSYS thermal analysis module. The numerical analysis is made on the temperature field of a certain type of Electric connectors at different environmental temperature and different working current. The simulation results are compared with the monitoring test data.

Abstract: The properties of chaotic maps based on Logistic map, Tent map, Improved Logistic map and Chebyshev map are analyzed in this paper .Then we discuss the performance of correlation, balance and run-length of the chaotic binary sequences . Simulation results show that the characteristics of chaotic sequences are similar to the traditional pseudo-random sequences, and chaotic sequence is suitable for direct sequence spread spectrum systems as spreading sequence.