Advanced Materials Research Vols. 291-294

Abstract: Based on the thin-wall parts easily deformed difficult processing characteristics, design the vertical ultrasonic vibration turning device which is suitable for thin-wall parts precision machining utilizing the superiority of ultrasonic vibration turning processing.This device mainly includes piezoelectric transducer, composite horn, tool, tools folder body and the installation device part, carry on the finite element simulation for transducer, solid horn and the entire device system and compare with the resonance frequency of practical requirements, thus proving the reliability of the thin-wall parts ultrasonic vibration turning device we designed.

Abstract: Reactive Powder Concrete(RPC) is a cementitious material that exhibits high performance properties. Brittle failure mode usually appears when it is subjected to high or complicated stress. The fragility performance of RPC can be great improved if efficient confinement is provided. In this paper, four RPC-filled steel tube stub columns under axial loads were analyzed using the finite element program ABAQUS. Two different axially loading modes were considered. The analysis results were compared with the results of the tests. It was found that the FEM models can predict the force-displacement relationship of such columns with acceptable accuracy.

Abstract: In this paper, the effect of material strain rate on the deforming process, the absorbing energy performance and the vehicle front longitudinal rails’ crash stress was researched.Furthermore, finite element model of a vehicle’s facial crash simulation was built up. Rigid wall facial crash simulation was carried out in two work conditions of considering front longitudinal rail strain rate and without considering it. Entire vehicle’s crash deceleraten was compared with test results. The results indicate that material strain rate has great effect on entire vehicle crash deceleraten, and the simulation result with considering material strain rate is more similar to test result than the one without considering it.

Abstract: To explore the impact of abrasive granularity, feed pressure and cutting feed speed on NC ultrasonic machining efficiency, a technological test was carried out, and based on the test results, back propagation (BP) neural network model was established and validated by simulation. The validation process showed that when relative error is less than ±10%, only two samples among 18 tested have larger errors. By the utilization of the BP network for training, correct fitting rate of machining efficiency target can be reached up to 88.9%. Our study indicates that (i) the output of the network is well fitted with the test data, (ii) the established model has good generalization ability to reflect the laws of NC ultrasonic machining process, and (iii) the model is suitable as a prediction tool for NC ultrasonic machining efficiency.

Abstract: This paper deals with the causes of a transversal crack in a steel slab with an l300×l45 mm cross-section by means of results from two models. Samples were taken from and around the crack in order to analyze the concentration (chemical heterogeneity) of the selected elements. Simultaneously, the concentration of elements at the surface of the crack was measured after the crack was opened. The chemical heterogeneity of elements was analyzed by means of the JEOL JXA 8600/KEVEX analytical equipment. The measurement results were processed using mathematical statistics procedures. The results proved that there was an internal crack initiating immediately below the curve of the solid-state temperature and consecutively propagating.

Abstract: The design and numerical simulation and analysis on non-pneumatic beehive damping tire were discussed in this paper by finite element techniques. And use the molding software filling its experimental to analyze the process of injection molding qualities for the reasonable mold design. And the corresponding improvement measures, the rationality of mold design and molding process were arised for quality issues according to the simulation analysis.

Abstract: An inner-outer coupled cooling technology of molten steel for 1240×200mm slab continuous casting, that is to set an inner cooler—U shape pipes in the mold, is put forward in order to enhance the efficiency of transmitting heat and improve inner structure of billet. The flow status and solidification status of molten steel under coupling flow field and temperature field in inner-outer coupled cooling mold are simulated by using fluid dynamics software, and compare with those in traditional mold. It is found that setting inner cooler in the mold can make molten steel flow status even, which is favorable to floating up of the inclusion, quickening the solidification of steel liquid and improving the quality of billet.

Abstract: The CNC milling machine is extensively used in manufacturing of the die and the box-type parts. However, the tool errors, which caused by the cutting heat and the cutting force, seriously affect the machining accuracy of the machined parts. Furthermore, the tool errors are too complex to be calculated by the empirical formula. To solve this problem, a tool error compensation method is proposed in this paper. The least-square method is employed to structure the error model. A weighting coefficient is proposed to adapt the various working conditions. The macro program is used to realize the real-time error compensation. Using the tool error compensation method, the maximum tool error is reduced from 0.053 mm to 0.005 mm. The error is compensated by 90.5% compared with no compensation.

Abstract: Based on the deep analysis of injection molding process and factors influenced on the quality of injection-molded parts, and considering of the non-linear, multi-variable coupling of process and the problem of data deficiencies, a feed-forward three-layer neural network was presented to predict the part weight based on the melt temperature, holding pressure and holding time, which is the most important quality index of injection-molded parts. Furthermore, an architecture optimization approach for neural networks was used and the performance of ANN was evaluated and tested by its application to verification tests with process parameters randomly selected which all of them were not used in the network training. Results showed that the ANN predictions yield mean absolute percentage error (MAPE) in the range of 0.1％ and the maximum relative error (MRE) in the range of 0.47％ for the test data set, and which can comparatively accurately reflect the influence relation of the injection process parameters on part’s quality indexs under the circumstance of data deficiencies.

Abstract: Due to the limitation of 2D simulation in fine blanking, finite element software DEFORM-3D was used to simulate the 3D model of Back Plate. In this article the Normalized Cockroft&Latham fracture criterion was chosen to simulate the blanking process. The distribution and developing trend of the hydrostatic stress, equivalent stress in the fine blanking process are predicted. When the die radii are between 0.4mm and 0.6mm, burnished surface improves. It shows that the ideal blanking clearance value is 0.6% of the material thickness. The results indicate that FE numerical simulation could effectively optimize fine blanking process and offer basis for quality improvement.