Applied Mechanics and Materials Vol. 487

Abstract: This paper presents a dynamic parameter identification method of the unknown object handled by manipulator. Since the load will change the dynamic characteristic of space robot system, it is necessary to identify the dynamic parameters of the handled object. The dynamic parameters of the handled object are identified based on principle of momentum conservation in this paper. The principle and experimental process of the identification is introduced and the feasibility of the method is verified by simulation.

Abstract: In order to increase calculation accuracy of CNC system reliability, this paper proposed a maximum likelihood parameter estimation method based on improved genetic algorithm. In the parameter estimation process for CNC system reliability distribution model, the maximum likelihood function value was gained by improving genetic algorithm through simulated annealing algorithm. Parameter estimation was carried out by setting Weibull distribution as an example. The result shows that the improved genetic algorithm can increase solution efficiency and convergence rate. Besides, it can effectively estimate parameters of reliability distribution model.

Abstract: K-criterion that is used to boundary line and brittle fracture is presented when the size of plastic zone around crack-tip is less than that of adaptive zone of K-criterion by comparison adaptive zone of K-criterion with plastic zone around crack-tip in this paper. Finally numerical examples are given to illustrate the applications of the present method by comparison with other methods.

Abstract: Recently, microfluidics system has been widely employed in various areas for instance biomedical,pharmaceuticals and cell biological researchdue to its advantages. The flow behavior in microchannels with different cross-sections has been topic in previous studies. In this paper, numerical simulation of fluid flow in Forward Facing Step (FFS) configuration was performed to investigate velocity profile after the step. Reynolds numbers (Re) 100 with different step heights, 1μm and 3μm were used to observe trend occurs in the flow characteristics. The result illustrated an increase of velocity distribution with the increase of the step height.

Abstract: Wall shear stress (WSS) is one of the important variables in microfluidic devices. In this paper WSS distribution for a microfluidic device in Forward Facing Step (FFS) configuration has been investigated using Reynolds number 500 and step height 1μm. Numerical simulation was performed usingAnsys-CFX software with the assumption of Newtonian fluid and laminar condition. The simulation result showed that wall shear stress distribution increased after the fluid passing through the step.

Abstract: A three-dimensional surface measurement using fringe projection technique has received attention among the researches for the last few decades.However choosing the best method is the challenge because one needs to consider the cost, measurement speed, system complexity, measurement accuracy and data reliability to ensure the success of the measurement. This paper focused on the successful manipulation of non-collimated light source and three step phase shifting for height measurement of a lead frame.The measurement done based on pixel determination from the saw tooth image. In addition, the scaling factor technique has been employed for the measurement accuracy. The experimental results achieved a high precision of measurement with simple system and high speed capability.

Abstract: When two slender pipes were girthed weld, some of un-solidified solder liquid would ooze from the weld gap. Then the weld beading would be formed in the pipeline after solidification. It is difficult to be cleared away because of the higher hardness. Up to now, there was no effective method to solve this problem. So how to guarantee the pipeline quality was a big question, and it would influence the benefit of companies seriously. This paper presents a new cleaner to solve this problem. The cleaner was driven by direct current motor, and the cutting tool mechanism was driven by pneumatic motor which can carry different kinds of cutting tools. For the question of passing through the bend, the cleaner was designed to specified size after accurate analyzing. And another significant part was monitor, which was mainly composed of camera and video. In the end, we designed a model cleaner and manufactured it. The cleaner had been tested on spot and achieved the desired effect.

Abstract: Vertical mill grinding system is one of the important cement grinding equipments developed in recent years. In this paper, through the industry vertical mill grinding GGBS carried out a detailed analysis of particle size, on this basis, using the attached to the sample preparation method, obtained the typical SEM images of GGBS through industrial vertical mill, and using particle image analysis software for slag microstructure has carried on the qualitative analysis, obtained the change rule of microstructure of the grinding process. Meanwhile, using shape index, roundness coefficient, flat degree, angularity and surface roughness quantitative characterization of the microstructure of slag powders.

Abstract: The new type of three jaw docking mechanism is designed for use in orbiting spacecraft, the mathematical model is given and its working characteristics are analyzed. By establishing the mathematical model of the interaction of the parts under the different coordinate system, it is obtained that the corresponding kinematic characteristics; contact collision dynamics model is established by using the Hertz model theory, dynamic equation is established by Newton-Euler method, and simulation analysis are carried out by using the dynamics simulation software ADAMS, through the simulation analysis of three groups with different initial conditions, the results show that it achieve reliable grasp with good performance, it provides the lock claw curve in contact collision force and movement characteristics curve. These curves provide reference to improve the performance of docking mechanism.

Abstract: In the three-dimensional terrain model construction, a lot of work is to modify the partial area of the discontinuous portion of the model, augmenting the descriptions of the detail and the authenticity of the model. In view of this, this paper mainly studied the influence of node transformation on terrain model. And combined with the primary technology of node transformation, the paper also analyzed the application of node transformation on a certain terrain model. The result indicates that: using node transformation technology can effectively develop the complexity and authenticity of the model, enhance the sense of immersion in the VR environment.