Key Engineering Materials Vol. 572

Abstract: The enzyme from Aspergillus versicolor A6 under solid state fermentation using agricultural waste as substrates were successfully produced by our group. Laboratory scale enzymatic retting for white pepper production was conducted using crude pectinase enzyme preparation found that decortications of green matured pepper berries were achieved after five days which is comparable to other commercial enzymes. Microbial specification and quality analyses found that retted berries meet the standards set by the International Pepper Community. This study presents a design and development of a machine which integrated mechanical and enzymatic solutions in the decortications of pepper pericarp to improve efficiency the production of white pepper berries as compared to conventional water retting method.

Abstract: A new approach of the teaching of the subject Graphical engineering is developed at the Engineering School of the University of Salamanca, focusing the contents on the use of the CAD/CAM/CAE systems as useful tools for applying engineering problems related with the mechanical engineering instead of describing diverse software options. Thus, the contents of the subject are divided into two blocks, one devoted to the analysis of the results of simulation of movement of diverse mechanisms and the second devoted to the analysis of diverse cases of loading structural components by means of FEA module, both available in the Autodesk Inventor Pro suite which can be downloaded free by the students. This way, students can visualize and realize of the complexity of a design process in engineering.

Abstract: Different types of graphs have successfully been used to represent different objects in design problems. Graph transformations are often used as a way to generate, update and modify such graphs. Typical use of graph productions assumes that change of a graph is done by applying a single transformation or a sequence of independent productions. Yet, in many real life design tasks the application of a production may depend on the possibility of applying other productions. Moreover the productions required to be applied usually only depend on the current graph so the set of productions cannot be defined apriori. In this paper we present a novel approach, called a transactional model, where a set of productions is dynamically chosen in a way that it is possible to fulfill a common goal.. Only if all of the productions can be applied the whole transaction is carried out. The approach is illustrated with the problem from the domain of architectural design.

Abstract: The instability flow in the control valve often lead to abnormal vibration, the valve wear and the valve stem destruction, also lead to pressure loss. The flow in the control valve show complex flow regime distribution and variation, it is a typical unsteady flow. Therefore, it is necessary to theoretical calculation and qualitative analyses the flow field of valve by the numerical simulation method. In this paper, we study on the axial force of valve stem that caused by the fluid pulsation pressure. Establishing the flow field model of the control valve, generating the computational grid through the pre-processor, using the CFD software to do discretized and solved, getting visualization graphics of the internal flow field. Study the changes of the flow characteristics according to different pressure ratio, getting the variation characteristic of axial force. Provide the basis for subsequent optimization and design of the low vibration control valve.

Abstract: This paper presents the results of numerical calculations of rolling extrusion process of a hollow hub. Due to the necessity of flanges manufacturing at both sides of the product, in the analyzed process of rolling extrusion, as additional tool limiting axial metal flow a rear bumper was implemented [1,. Numerical calculations of the hub forming process were conducted basing on finite element method, applying software Deform3D v.X in conditions of three dimensional state of strain. The obtained small shape faults, in the form of characteristic triangulation and small changes of the hub walls thickness, show that it is possible to conduct the further research works of experimental character, with the application of modernized aggregate for the rolling extrusion process PO-2.

Abstract: t is high in efficiency to cut rectangular steel pipes with flame cutting mode compared with milling mode, and it is simple in processing equipment. When cutting the four arc angles of steel pipe, the steel pipe carries out the uniform rotational motion while cutting torch carries out plane two-dimensional motion, in order to achieve uniform motion in a straight line relative to the round arc angle of steel pipe. The rotation speed of steel pipe is proportional to the cutting speed. And the X component and Z component for the speed of cutting torch will respectively change according to the sine and cosine curves. The space geometrical relationship and motion relationship of round corner torch track and steel pipe corner are described by means of parametric equations. And the correctness of the algorithm in CNC rectangle pipe cutting machine has been verified.

Abstract: In the today’s industry the sheet metal design plays a huge role, it has been said that almost the half of the designing is concentrating to sheet metals. But the lack of knowledge of the typical sheet metal aspects and basic rules of sheet metal designing, has led in to situation where more and more products are poor designed. This automatically leads to situation that the products are not manufacturing friendly. Designing time is shortening year after year, so the pressure to design the part as fast as possible is huge. Unfortunately all the design information and the design intent is processed and filtered to be fit for the Product Data Management (PDM) system. As the PDM was firstly designed to be used only for the storage base for the design drawings and other data; the feature-information and design intent is lost. This paper deals with two distinct yet interlinked themes. The first theme is the new requirements set for the new Product (Life-time) Information systems that can save the product information and design intent. And the second theme is the modern, light-weight and updatable product-services that allow the manufacturability to be ensured before product realization. With the help of novel product-service such as Design Manufacturing and Assembly (DFMA) for sheet metal industry designers will able to design in shorter time manufacture friendly sheet metal products.

Abstract: Disassembly Sequence planning is the important module of virtual maintenance. Its foundational task is to test the disassemblability of parts, find out all the feasible disassembly sequences of targeted parts and search for the near-optimal disassembly sequence. In the paper, the spherical algorithm is used to test the disassemblability of parts. And then the disassembly direction of parts is determined by rules which are the simplified version of Gaussian map approach. Thus the near-optimal disassembly sequence is found out by optimizing all feasible disassembly sequences of targeted parts by ant colony algorithm. The simulation result of the sequence optimization proves to be the same with manual calculation considering comprehensive cost of the change of disassembly tools and disassembly directions. The set of approaches can be reference for disassembly sequence planning of large-scale mechanical products.

Abstract: Disassembly of scrap product is a necessary procedure of products recycling and reusing, which is an important part of whole life cycle of the products. Scrap product disassembly process planning can reduce the cost of disassembly operation. It can also improve operation efficiency and the enterprise competitiveness. A new improved algorithm is developed based on the basic ant colony algorithm, which is poisoning ant colony algorithm. Poisoning ant colony algorithm is applied to realize the search and optimization for feasible disassembly sequence solution set with disassembly root diagram. Finally, the optimal sequence is obtained based on evaluation objective function. Toxic environment and life value are also introduced to this algorithm. The characteristics of the algorithm are preferable search and convergence property.

Abstract: Conoprobe is used for non-contact measurement utilizing conoscopic holography technology, which has characteristics of high measurement precision and large measuring angle range. However, the conoprobe performs inaccurate and instable in gear measurement applications. To verify its accuracy, an experiment setup is built using high performance coordinate measuring machine (CMM) to measure surfaces of gaugeblocks that have similar material as gear workpieces. Compared the collected data from the CMM with the conoprobe values, those problems mentioned above are validated. In this study it can be stated that measuring accuracy of conoprobe drops dramatically when measuring bright metal surfaces, and even its measuring error could be more than dozens of microns when the measurement is in large angle, therefore it is completely not fit for precision measurement applications.