Advanced Materials Research Vols. 591-593

Abstract: Based on the additives of system function, and the co-dependence between the system and subsystems. We analyzed the optimization of co-dependent and absolutely additive system followed after the paper The optimization of independent and absolutely additive system. We make further efforts to analyze the performance function of absolutely additive system, the variation of co-dependent and absolutely additive system performance function, and building the optimization model of co-dependent and absolutely additive system based on the performance function, and giving an example.

Abstract: The problem to determine the width of a 3D object is involved in many engineering fields. This paper presents an optimized iterative projection method to solve this problem. In this way, the 3D width problem is turned into a 2D width problem, simplifying the solving process greatly. Furthermore, several improving strategies are addressed to reduce the amount of calculation and enhance the executing efficiency of the iterative projection approach. Experiments of models and point sets are also given to show the prominent performance of the proposed algorithm.

Abstract: Technique problems on motor security analysis and management are solved based on fuzzy theory. Combining such theory with present research of car engine structure and its related technique, based on abroad investigation of car engine malfunctions, index system suitable for motor engine security analysis is developed and fuzzy theory, a mature theory in the management science is induced in the security analysis. In the study, method and techniques for car engine security analysis and management are proposed. The real case proves that this index system and analytical technique are applicable, the analytical result could be used as theoretical references for security management, production manufacture and improvement, it could be used for analyzing similar automobile products.

Abstract: For improving the designed quality of the cycloidal gear planetary drive, the paper derives a calculation formula of the minimum film thickness, which is between cycloidal gear teeth, based on elastohydrodynamic lubrication theory and gear geometry. A mathematical model for constrained multi-objective optimization is established and the model satisfies three constrains:maximize minimum film thickness between gear teeth( minimize the reciprocal ), minimize average value of m points’s absolute error value on active section that is between the tooth curves of positive shift optimal combination and tooth curves of rotated angle’s modification, minimize the total volume of gear drive. The paper abandons traditional designed method of the multi-objective optimization , improves two-objective particle swarm optimization and offers a new designed model for constrained three-objective optimization. The example is analyzed and the optimization program is complied using Matlab. The optimization’s process and result shows that the method of improved constrained multi-objective particle swarm optimization could effectively improve the products’ synthesize economical and technical indexes.

Abstract: Suitable maintenance policy implemented in particular machine able to improve the machine performance as well as the product quality. However, selecting a suitable maintenance policy is a vital and hard work because it has to be decided from analysis of various criteria including failure mechanism and resources limitation. Thus, decision tree is suggested in this paper to provide assistance for maintenance crew in conducting a systematic and efficient decision making process in determining the suitable maintenance policy. In the end of the paper, a case study in semiconductor industry is conducted to illustrate the practicability of developed decision tree.

Abstract: Maintenance is a vital component in ensuring machines to run smoothly. While, maintenance technicians are responsible in conserving the conditions of machine by performing regular inspections. This study was conducted to investigate the performance of maintenance system in a company by identifying the critical machine with the highest breakdown frequency and time. It was found that high breakdown was due to the high workload of technicians, where no extra time can be allocated for thorough inspection task. Technicians do not have enough support in performing maintenance task. In this paper, Autonomous Maintenance (AM) program is suggested to reduce technicians’ workload through operators’ involvement. Technicians work is reduced with the aid of operators, which gives them more time for other maintenance tasks. The AM process flow is implemented in a case study company as a verification and validation processes.

Abstract: Objective The principle and method of the force application is researched in orthodontics field, providing the scale and location of force for clinical orthodontics. Methods Reverse engineering software is used to reconstruct a 3-D mandible finite element model, the MBT bracket and straight archwire on the dentition are modeled on it. Change the elastic module of archwire to simulate four stages of orthodontics and the displacement and stress on dentition and mandible are acquired. Results The finite element results of dentition and mandible under short Ⅱ elastics are obtained, the results show that titanium-nickel archwire may provide major displacement for dentition; O and stainless steel have good force-transmission in teeth. The stress of single tooth and mandible are symmetrical except for the position where loads are applied. Conclusions Under the short II elastics loads, bone absorption don’t appear and the bodily movement of mandible is arose.

Abstract: The perpendicular climbing obstacle capability of omni-directional wheeled robot was studied, based on simplified mechanics model. The relation between influential factors and perpendicular climbing obstacle height was given under two conditions: simultaneously climbing obstacle by two front wheels and simultaneously climbing obstacle by two rear wheels. Then maximum perpendicular climbing obstacle height of this omni-directional wheeled robot was calculated. Simulation analysis to the result by MATLAB was done. The simulation analysis gave theoretical foundation to the climbing obstacle capability of omni-directional wheeled robot.

Abstract: On the basis of the finite element analysis model of the wind turbine flange, this paper studies the fatigue damage of the MW wind turbine flange, analyzing the fatigue stress of the wind turbine flange with MSC.Marc/Mentat software, realizing load simulation of flange fatigue case with Bladed software, and calculating the fatigue loading spectrum of the flange with the method of rain flow circulation count. The fatigue damage calculation method which combines the rain flow circulation count method with Palmgren-Miner linear cumulative damage law, is proposed to modify the S-N curve of the flange material according to GL standard. The result shows the method feasible and reliable which provides one more accurate analysis idea for the fatigue life of the wind turbine generator system top flange.

Abstract: This paper uses non-linear finite element method to structurally analyze top flanged joint system of a MW wind turbine, sets up a finite element model of top flanged joint system by applying finite element analysis software MSC.Marc/Mentat, makes an analysis on the stress distribution of key components of top flanged joint system under ultimate operating mode based on applying appropriate boundary condition and loads, and carries out security examination on top flange and joint bolt. Result shows that key components of the top flanged joint system can satisfy design requirements, and it has a guiding role for rational design and performance improvement of large scale wind turbine flange, which can be used in structural analysis of other flanged joint systems, and has certain practical value in the aspect of engineering.