Advanced Materials Research Vol. 421

Abstract: Aim at the characteristic of airplane assembly sequence evaluation, which has too many rules, and the quantity process of qualitative rules is too complicated, this paper presents an evaluation mode based on the fuzzy theory and the multi-index progressive model. According to the evaluation rules space and the coefficient distributed method of rules compared, it divides the rules space into force associated decision-making gather and weak associated decision-making gather by defining the cut value. Then it adopts the maximal subjection fundamental to implement the function of assembly sequence evaluation. An instance about airplane sub-assembly is used to prove this method can solve a practical application availably.

Abstract: The artificial knee joint need to satisfy and meet certain design requirements in addition to being biocompatible. These being the design of the flexion angle and sagittal radius of the prosthetic knee for specific activities such as walking and exercising. Day to day physical activities do result in generating frequent contacts between the femur and tibia leading to stresses at the interface of the femorotibial joint. These stresses on exceeding certain limit do result in damage of the tibia which acts as bearing surface carrying loads during each of the knee activity. Hence, prediction and minimization of the stresses at the knee interfaces is the key issue to ensure high performance knee joints. In the light of the above, the stresses at the knee interfaces are computed using commercially available FEA software (ANSYS 10). The three dimensional model was developed using PRO E software for sagittal radius of 40, 50 and 60 mm. The flexion angles considered are 0, 20 and 40 degrees. A load of 500N was considered. It is observed that the stress intensity increases with increase in flexion angle and sagittal radius for all the material combinations of the prosthetic knee joint. Further, alumina ceramic femur and polyethylene chopped carbon fiber composite tibia exhibits the least stress levels at all the studied sagittal radius and flexion angles.

Abstract: In order to model complex product systems and analyze their whole performance to deal with the coupling relationships between multi-domain，aircraft landing gear selected as the object, unified multi-domain modeling and simulation and for complex product systems was studied. The aircraft leading gear is decomposed as structure, and the mathematical models of the landing gear components are established. The model library of the landing gear components was developed using Modelica-based platform and multi-domain unified model of the landing gear was established. The impact work amount, the vertical load and the stroke are selected as the indexes to simulate and analyze the earthquake resistant performance of the shock absorber.

Abstract: Making a CAPP system which has both practicality and versatility is still a problem to be solved. Aiming at this problem, an idea of developing an integrated derivative and retrieved type of CAPP tool system is presented, and combined with a development practice, the structure and some key technologies of the system is also introduced.

Abstract: To improve precision of reverse design in cam contour curve, method of using BP neural network was presented. The theory and algorithm of BP neural network were introduced, the principle and process of BP neural network modeling used in the reverse design of cam contour curve were expounded, and the actualize method of reverse design with modeled network was afforded. Experiment indicates that this method is suitable to reverse the contour curve of cam, and has high approach precision. At last, disadvantages of the method were discussed.

Abstract: Network Security serves as a guarantee for achieving collaborative design and enabling network to be highly efficient. The hidden security lapses in the frame of traditional collaborative design system are analyzed in this paper. The author also points out that as for a sound network collaborative design, a security mechanism must be established to secure the system in terms of data transmission and personnel action. A comprehensive security mechanism involving VPN encoded transmission, identification based on projects and authority management according to different roles.

Abstract: In this paper， conception and method of bias and linearity analysis of measurement system are introduced , Minitab software are used to analyze bias and linearity of measurement system of MEMS microphone frequency response and sensitivity, conception of composite measurement system is put forward, and having effectively analyzed for it .According to the study result, the method which use whole bias value correct measurement system is discovered ,and forecast the improved measurement by using Minitab software system, after it is used product practice , greatly enhances reliability of measure data of MEMS microphone measurement system.

Abstract: Polymer vane extruder is a new type of extrusion machine, whose plasticating and conveying method is based on elongational rheology. The vane extruder has many advantages over conventional plasticating method, such as shortening thermo-mechanical experience of plasticating and conveying, reducing the energy consumption of plasticating and conveying, and improving adaptability to diverse materials. Currently, research for characteristics of vane extruder is mostly focused on theoretical derivation and experiments. However, these methods lead to high consumption of time and energy, and cannot provide an intuitive view of the flow. In this paper, 3D finite element numerical simulation was performed to investigate the flow in one of the vane units with POLYFLOW. The elongation flow was investigated by analyzing velocity field, pressure field, local-shear-rate distribution and mixing index distribution. The results show that numerical simulation is an efficient method to optimize process parameters and the structure of vane extruder.

Abstract: In Reverse Engineering (RE), Point Cloud Data (PCD) processing is of great importance. But at present, a number of key issues about its algorithms are unresolved. This article mainly introduces the author who has done the research and put forward some specific algorithms on the aspects of data topology reconstruction, multi-view data registration and data reduction, and then developed a PCD processing system --3DPointshop, based on OpenGL and MFC. Through a series of instances of tests show that the prototype system which contains the algorithms and function modules will be able to implement on PCD processing well and could achieve the practical application level.

Abstract: Planomiller is a milling machine that widely used in processes of large parts. Cistern stents is a component of planomiller supporting the sink. In this paper, topological optimization of Cistern stents is implemented to reduce its weight. Firstly geometry model of Cistern stents is built in SolidWorks, a finite element model of Cistern stents is established. Then loads and boundary conditions are loaded to the finite element model according to engineering practice. Finally density of units is set as the design variables, energy of structural deformation is set as the objective function, Cistern stents can be optimized by optimizing analysis. The compared results show that the proposed optimization design is effective.