Advanced Materials Research Vols. 201-203

Abstract: The interdependent relationship of fatigue stress and span was regarded as a grey system using grey system theory and method. The stress level of fatigue test was uniformly divided into many grades and the whiting value of safe span was found out. A smooth discrete function was formed based on one accumulation of safe span value series. Therefore, the model of grey system was set up and the differential equation of grey system was solved. The accuracy of model was improved by revising the residual model. The safe span value at every stress level could be calculated using the reduction model of the grey system. It provided a new way for the safe span calculation of mechanical parts, which would be of great application value.

Abstract: Digital video camcorder is a kind of mechanical and electrical product that is easy to make misoperation. Chose green hand users as subjects.Then applied experiment method to study their misoperation manner in using Sangsumg VP－101 digital video camcorder. According to industrial design psychology and ergonomics theory , analysed experimental result. Firstly, through F testing of psychology statistics method, found that the major effective reason of misoperation was task difference which was relevant to interface and interacting means design factors, and individual difference of each subject had little effect on misoperation. Secondly, in terms of analysis on the relevance of interacting means design details and misoperation manner, found rational design reasons of misoperation. They were mismatching attribute of perception, mismatching attribute of touching size, lack of visuality. Thirdly, On the basis of statistics on subjects mood research, found that nervous and whiny mood were irrational factors affecting misoperation. The conclusion could be summarized as the three results mentioned above. Specific to this conclusion, discussed methods to deduce misoperation by building user task model, user mental model and green hand user mood model.

Abstract: In this paper, a new method, so-called finite particle method, for form-finding of tensegrity systems is proposed. It models the analyzed domain by finite particles instead of mathematical functions and continuous bodies in traditional mechanics. Examples including simple regular tensegrity systems and complex irregular tensegrity systems are carried out to verify the feasibility and effectiveness of the method. Also a comparison between the proposed method and the dynamic relaxation method is conducted. It proves that the proposed method is much more effective than the dynamic relaxation method in the form-finding of large-scale tensegrity systems. Hence, the proposed method has a great potential of developing into a general and effective form-finding method for irregular and large-scale tensegrity systems.

Abstract: In view of (Considering)the fuzziness of attribute information in process of scheme design for electromechanical product emphasizing both form and function, the construction methods of evaluation index during evaluation and decision-making on the scheme is studied, the construction methods of evaluation index system based on technology, aesthetics, economy and society is proposed, and the comprehensive evaluation and decision-making model of product design scheme that integrates Analytical Hierarchy Process(AHP), Triangular Fuzzy Numbers(TFN),and Gray Relating Analyze (GRA) is established. With evaluating and decision-making on three electric hair dryer cases, the effectiveness of the model and method is demonstrated indirectly by the contrast between the result and the share of sales of three electric hair dryers on the market.

Abstract: A model of two thinking paths is developed in this article. Early researchers of computer aided for product design focused their attention on sensation of consumers on product appearance to meet the consumer need. However, these generative rules of digital form did not consider the thinking process during design concept development. The experiment was designed to explore the concept transformation of two thinking patterns, and the shape generation in design thinking developing. The martini wine cup had been selected as a design target to collect the data. The model of two thinking paths was then developed based on results of the design thinking experiment. An experimental system, called thinking pattern-based generation system, a.l.a. ThinkGen, was then implemented to test the model.

Abstract: The principle and characteristics of Fault-tolerant Permanent Magnet Synchronous Linear Motor are introduced. The design or computational method of the polar distance of concentrated winding coil, the armature parameters, the armature winding parameters, the coil diameter, the distance from the adjacent armature windings are given. The magnetic thrust equation is derived, and the core issues are analyzed. It provided theoretical basis for structural optimization of the Fault-tolerant Permanent Magnet Synchronous Linear Motor.

Abstract: According to the hot rolling technological requirements on the bearing-steel-ball blanks, an automated conveying system program was proposed. The primary structure and the characteristic of this automatic conveying system was introduced as well as the working principle of it. It was found that the system possessed the advantages such as higher feeding accuracy, good job stability and rational construction and it can meet the process requirements.

Abstract: The challenges facing the subsea production system are becoming increasingly complex with hydrocarbon production moves into deep and even ultra-deep waters. As the most critical equipments, subsea trees need to be designed synchronously against the increasing technology gaps. This paper highlights the common considerations for subsea trees design, especially the horizontal Xmas tree, towards future deepwater application, and the main contents consists of structure design combined with subsea seal technology and the important thermal design in terms of insulation materials selection and application, numerical simulation. Meanwhile, some suggestions and application cases are also included in this paper.

Abstract: The torque ripple of brushless dc (BLDC) motors at low rotation speeds is prominent, while in the majority of working time of the automotive electric power steering (EPS) system, the steering rate is low and the assistant motor runs at low rotation speeds. Therefore, to develop a high-performance EPS system with a BLDC motor, the problem of torque ripple at low rotation speeds must be solved. Otherwise, the steering feel will not be smooth. This paper proposed an algorithm based on BLDC motors’ essential torque formula combined with the back-EMF (Electromotive Force) waveform coefficient to modify the target current to suppress the torque pulsation effectively. Meanwhile, the commutation process of this type motor is very short. Therefore, the torque coefficient can be regarded as constant during the commutation intervals. A direct pulse-width modulation (PWM) control method considering phase resistances is analyzed with a unipolar PWM scheme to reduce the commutation torque ripple further. Finally, simulations and experiments are conducted to verify the effectiveness of this method.

Abstract: A practical flapping wing micro aerial vehicle should have ability to withstand stochastic deviations of flight velocities. The responses of the time-averaged thrust coefficient and the propulsive efficiency with respect to a stochastic flight velocity deviation under Gauss distribution were numerically investigated using a classic Monte Carlo method. The response surface method was employed to surrogate the high fidelity model to save computational cost. It is observed that both of the time-averaged thrust coefficient and the propulsive efficiency obey a Gauss-like but not the exact Gauss distribution. The effect caused by the velocity deviation on the time-averaged thrust coefficient is larger than the one on the propulsive efficiency.