Advanced Materials Research Vols. 472-475

Abstract: Analyzes the reason why renitrocarburized element could not get desired surface quality as the first. Improve the craft. Conduct trial and testing. The surface hardness and compounds layer depth of the Renitrocarburized element can back to the same level as the first time. Furthermore, the infiltration layer microstructure is consistent with that in the first nitro carburizing.

Abstract: The stress distribution of structure in plan coil spring usually is three dimensional. The singularities of Cauchy principal integral and logarithmic integral during calculating the elements of the coefficient matrix are studied respectively so that the singularity of Cauchy integral is eliminated in this paper, which is based on boundary integral equation in axisymmetric potential problem. Moreover, the order of singularity in logarithmic integral is reduced. Comparison between the results deduced here and the analytical solutions shows that the present derivation is correct and the algorithm is efficient as well.

Abstract: The PET fabric surface was modified with ultraviolet radiation and nano-TiO2. The wettability and the broken strength of the modified PET fabric were studied. The results showed that with the increase of the ultraviolet radiation irradiation, the water contact angles of modified PET fabrics decreased greatly. Water contact angle of PET fabric modified with 40g/L nano-TIO2 and 60 min ultraviolet radiation irradiation could decreased to zero in 4.11 seconds. And the capillary rise height of modified PET fabric could increase from 1.1 mm to 110.2 mm. The spraying rate of modified fabric could decrease from 4 to 1 degree, and the water absorption could increase 89.86%. These showed the hydrophobic PET fabric could be modified to super hydrophilic PET fabric. The broken strength of modified PET fabric not only did not decrease, but also increased a little. The broken elongation kept well.

Abstract: Tensile experiment of AZ91D magnesium alloy was carried out and serrated flow was apparent throughout the deformation history. Dynamic strain aging (DSA) occurs when the AZ91D magnesium alloy treated by solid solution treatment has been deformed at a set range of strain rates (1.11×10^-4 s^-1 to1.67×10^-3 s^-1) and a certain range temperatures (248 K to 423 K). The critical plastic strain εc was observed to increase with increasing strain rates but decrease with increasing temperature. The diffusing activation energy of solute atoms during the DSA occurring in AZ91D magnesium alloy is 140.8 kJ/mol by calculating, which is correspondence match with the diffusing activation energy of Al solute atoms in Mg matrix. Therefore, the micro-mechanism of DSA in the alloy is believed that the Al atoms in solid solution gather around dislocations to form Cottrell solute atmospheres by vacant diffusion and then pin the moving dislocations.

Abstract: The springback is one of the phenomena in sheet metal forming. It is very important for bending dies and sheet metal part to predict springback amount. In this study, according to different material models and different methods, the formulas of the radius of curvature in the neutral layer and springback angle after loading removing are given based on the principle of sheet metal bending. The results from the formulas of the radius of curvature in the neutral layer and springback angle, and experiments are compared. It is analyzed that the factors influence on springback and accuracy of the formulas. The results show that it is little difference for different formulas. The results from the formulas of the radius of curvature in the neutral layer and springback angle after loading removing close to the experiments.

Abstract: This study introduces the current states and progress of the overseas digitization manufacture technology of airplane ducts, and analyzes the problems about manufacture technology of bent tubes in airplane production in China. Thus, instead of the full pattern, the three-dimensional models are proposed to conduct the NC(Numerical Controling) bending and examine the bending quality, and the integrated digitization manufacture technology of airplane ducts is developed. The key problems are solved including standardization modeling of ducts, 3D data transfering, virtual processing analysis, digital modular fixture design/manufacturing, and NC bending/manufacturing/inspection of ducts. The technology has been successfully applied into the digital forming manufacturing of airplan ducts.

Abstract: A rapid product quoting model for Mass Customization was proposed. The case library of product quoting was established which include cases of the past year .Each customization parameter was assigned the corresponding weight based on AHP. Weighted similarity was applied to calculate the similarity between historical instance and the customization product, and the similar case group of the customization product was established. The assistant decision chart of cost estimation was drawn by adopting Exponential smoothing，and the key quotation point calculated. The detailed implementation procedures were given. The proposed methodology demonstrates the effectiveness in an instance of bridge crane quoting.

Abstract: The time-series is the collection of chronological varying numerical ordered by time. It has a wide existence of image data, text data, hand-written data and the brain scan data patterns. The present research of time-series concentrates on series data transformation, similarity search, forecast, classification, clustering and Visualization etc. Furthermore the trend forecast of time-series is the major basis of other related research. This paper analyses the existing time-series forecasting methods and puts forward a new time-series method based on principal component analysis. The example tests the validity of the method of other related research.

Abstract: Along with the rapid development of economy, strong demand has been put on the application of basic geographic information data which needs timely updating. It has become a subject to be further investigated to make full use of other data (such as forestry resource data, land survey data, etc.) to effectively add new data when the basic geographic information data is updated and ensure the timeliness of basic geographic information data. This paper gives an instance to describe and discuss a novel method, whose purpose is to quickly update basic geographic information data by forestry resource data on MicroStation V8 platform.

Abstract: Assigning welding spots to stations in the design of an auto-body welding line is a tedious job and error-prone. In this paper, an automatic processing system of welding spots has been implemented on the platforms of the commercial software, CATIA and Solid Edge. The geometric feature based technology is used to recognize welding spots automatically. The corresponding station is found for each welding spot according to the order of stations and the types of welding spots automatically. The system provides other convenient functions to facilitate the processing of welding spots as well. It has been used in the design of auto-body welding lines very successfully.