Applied Mechanics and Materials Vols. 201-202

Abstract: Micro-cracks on cutting edge will cause early breakages on cutting tools, accelerate tool wear and reduce cemented carbide tool life. Edge preparation can improve the cutting edge quality. Vibration polishing experiments were carried out for cemented carbide inserts edge preparation. Inserts and fixtures were put into the vibration polishing equipment which forced abrasive particles to collide and polish inserts. Edge preparation for fixed type insert and free type insert were compared with three sizes of abrasive particles. And the polishing time was changed for each testing cases. Experiments were carried out by altering polishing time, abrasive particle size and tool clamping way to determine the optimum technology of vibration polishing edge preparation. The experimental results showed that edge breakage numbers of insert significantly reduced. Smooth and round cutting edges were observed by optical microscope after edge preparation. Edge preparation experiments prove that edge preparation can change the cutting edge geometry and improve the cutting tool quality.

Abstract: Edge preparation is not only the process of grinding proper geometry of cutting edge or removing micro-cracks on cutting edge region, but also a way of improving cutting tool life. In this study, cutting models with different cutting edge radius were set up with FEM software. Medium carbon steel cutting tests were carried out using cutting tools with different edge radius. Cutting tool wear was simulated and measured for comparison. The simulation results show that edge radius has influences on tool wear. Tool cutting behavior is concerned with edge radius. A proper edge radius will improve the tool life. The experimental results show that proper edge preparation could improve tool impact resistance capability and reduce tool wear. The cutting tool life can be prolonged with suitable edge preparation. Edge preparation can improve cutting performance of cutting tool.

Abstract: By the combination of orthogonal experiments and moldflow simulation analysis, the warpage of a food tray is analyzed under the combined effects of multi-molding process parameters. By this method, it can gain the experiment data which can basically reflect the overall situation using fewer number of simulation analysis. In addition, the effects degree of different molding process parameters for warpage are researched, and the optimized parameter combination is obtained. It can avoid the one-sidedness of individual analysis of the various factors and solve the unreasonable appearance of process parameter settings. With the help of results, it can fasten the mold developing schedule, thus shorten the cycle of product development, and improve the quality of products and the competitive ability of enterprise.

Abstract: It is extremely meaningful to identify the processing dosage which directly influence the processing time, quality and other processing factors. In order to obtain the trend of lathing processing dosage, ordinary horizontal lathe was researched using the power signal frequency spectrum method, through the frequency distribution and the differences of amplitude, the trends of lathing processing dosage was identified. The collected current signal was turned into power signal first, when the cut depth is large, it is able to identify the trends of processing dosage through the fluctuations of the power signal, but when the cutting depth is small, compared to the power signal of idling state, there is not obvious difference to distinguish them. In this case, the frequency distribution and the differences of amplitude of the power signal were introduced.

Abstract: The selection and optimization of screw rolling ball process parameters were analyzed and discussed. The inner stress of ball is the major factor that affects the ball quality during screw rolling of ball. The inner stress is apt to be affected by other related process parameters. In practical, there is no specific measure to determine the parameters. In view of this situation, the influences of roller obliquity, rolling temperature, speed of roller and the outlet distance between guide boards and other parameters on the inner stress of ball were analyzed respectively through orthogonal test. The optimal combination of parameters was found through comparative study on several parameter combinations.

Abstract: The porous Ti-HA bio-composite was fabricated by powder metallurgical method with use of hydroxyapatite powder, Ti-6Al-4V powder and ammonium bicarbonate (NH4HCO3) powder. The experiment was aimed to explore the preparation process and to study the microstructure and mechanical property. As molding pressure increased, the compressive strength of material increased while the porosity decreased. As NH4HCO3 content increased, the compressive strength decreased, but the porosity increased. The results showed that NH4HCO3 content was 20wt%-30wt%, the porosity distribution was 30% to 50%, the compressive strength was higher than 20MPa and the pore size distribution was 100-500μm. This porous composite was suitable for bone repair material of human cancellous bone.

Abstract: The use of cross-wedge rolling method in metal-working industry allows development of new high-productive low-waste technologies designed to produce shaped billets for subsequent precision forging or other plastic forming processes. The paper deals with spheres of application, advantages and disadvantages of flat and roller cross-wedge rolling schemes. The equipment and tooling for flat cross-wedge rolling are described.

Abstract: To improve the accuracy and efficiency of warp knitting CAD, a new approach to texture segmentation and contour extraction based on wavelet-transform, K-means clustering and Canny operator is proposed in this paper. The procedure is described as follows. Firstly the Daubechies wavelet and pyramid-structure is selected, then the approach decomposes the low frequency part of the fabric image. Secondly starting from the highest scaling level and considering all the four sub-bands, the image is automatic clustered and segmented by K-means clustering. During the process we should calculate the average mean and standard deviation of the three high-frequency coefficients at the current level and transform the higher scaling level label values to have the same mean and standard deviation. Lastly the texture’s contour of image is traced and extracted by Canny operator. The results show that this approach is a feasible way for jacquard fabric.

Abstract: Although EPC mode has been applied increasingly in the past decade in China, the outcome of its implementation has been proved to be unsatisfactory. Actually, in most of our EPC projects, their supply chains are filled with various kinds of waste and luxurious coordination cost mainly due to uncooperative behavior and adversarial relationship among construction supply chain (CSC) parties/actors. These problems have greatly affected the effectiveness of our EPC project management as well as the comprehensive performance of our CSC. The reason can be largely attributed to the lack of advanced project management thinking and appropriate EPC project management model. This essay is to introduce lean construction supply chain management model to EPC project, aiming at applying lean thinking as well as relevant lean technologies to solve the major problems of our EPC project management and improve the overall competence of our CSC. It also fully discusses some key issues closely relevant to the implementation of LCSCM in EPC project.