Applied Mechanics and Materials Vol. 454

Abstract: The extended NGM (1,1,K) grey forecasting model had the defined type and white type mismatching problem. It proposed the extended NGM (1,1,K) model to eliminate the inherent bias caused by mismatch, the model also had given the prediction formula. Compared to the GM (1,1) model, the extended NGM (1,1,K) model had higher fitting and forecasting accuracy. The model was applied to spectrum prediction of Fe concentration of the oil in a certain type of military launch vehicle hydraulic system, it could determine the working status of the hydraulic system effectively combined with Fe concentration thresholds, the result show that the model is effective.

Abstract: Knowledge discovery model of making-decision table was established based on rough set theory and the wearing characteristics of the military launch vehicles hydraulic system. Compatibility relationship of the incomplete information system was used to achieve knowledge discovery from decision-making tables. Incomplete information systems knowledge representation which based on attribute reduction had been simplified, it had obtained simple and intuitive decision rules. The rules indicated that only monitor the normal wearing debris and non-ferrous debris in hydraulic oil could determine the wear state of the hydraulic system.

Abstract: This text apply UG software to the design and study on the type parameter of the brakes. On the basis of the principles of discretization, discretize the structural pattern of the brake drum. select the typical characteristic of the brake assemblies and the individual parts of the 3d parameterization modeling work, to build a model for parameterization library calls.

Abstract: The error analysis of the on-line measurement system used in the processing parts of numerically-controlled machine is investigated, and the image processing technilogy is analyzed through the investigations on error source, error analysis and geometrical error analysis, in which, much consideraton is paid to the image treatment and the object margin extracting process conducted to the images segmented and disposed in terms of image preprocessing and segmentation. Therefore, such an investigation is of great importance to enhance the machining precision of parts.

Abstract: A chemosensor was designed, and its sensing behavior toward metal ions was investigated by fluorescence spectroscopies. The fluorescence measurements indicated that the PcOC8 has excellent fluorescence emission in methanol solution, and the intensity of fluorescence emission was enhanced by adding Mg (II) ion, whereas other ions including Zn (II), Ba (II), Ca (II), Ni (II), Co (II), Cd (II), Cr (II), Fe (III), Pb (II), Cu (II), and K(I) could quench the intensity of fluorescence emission, which constituted a Mg (II)-selective fluorescent chemosensor.

Abstract: In this paper, vibration information of rolling bearings under 5 working conditions, including normal bearings, bearings with wear and tear on the outer circle or running pulley and so on, are collected. Obtained the relationships between parameters of service life of bearings and changes of time, such as the amplitude range, the frequency domain, and the energy around wavelet packets. Summarized a more detailed regular pattern for bearings wear and tear.

Abstract: This paper puts forward a multi-robot system which is made up of the MOTOMAN - HP3 serial robot and NPT800 parallel robot. Based on the mechanics model and dynamics equations that are established of the robot, the mechanical characteristics of the end for the grinding are analyzed. By applying the constant load and the functional load on the polishing end, the force and torque diagram for each of the robot arm joint are obtained. In the end, the conclusion that the force and the torque of the first joint is the largest can be obtained and the force of joint can keep the good constancy.

Abstract: For the structure optimization design of grinder Cui Zhong etc. [1,2] studied problems such like to select sample points which are used to structure the approximate model, to apply optimal Latin hypercube principle in the experimental design, and to take advantage of radical basis function. To minimize error they optimized models by using mathematical programming also. In our paper here using the methods in [1, we construct a model using CAD for grinding components, on the basis of optimum structural design procedure we deal with grinding spindle with structural analysis, sampling point selection, and optimum design, such that we greatly improve the design of high-speed grinding spindle on the wheel frame of CNC8312A[.

Abstract: In order to get brittle shear characteristics of rock material, acoustic emission accompanied with triaxial stress-strain test was applied to monitor the emergence and development of micro cracks. Theoretical analysis and data processing were conducted based on the theories of fracture mechanics and general rock mechanics, relations between the feature strength of three stages and the stress state were obtained, and a method was put forward for analyzing the brittle shear failure of rock material. The relationship of the Mohr-Coulomb strength theory, Griffith strength theory and Hoek-Brown criterion with the brittle-shear strength model were established. Strength analysis of mixed granite in Shuichang slope was carried out by the brittle shear failure model, and the theoretical value and experimental value has a good consistency.

Abstract: The elasto-plastic analysis using the triple shear unified yield criterion and the cavity expansion theory is devoted to soil around the tubular pile. When the influence of the intermediate principal stress is considered, the driving effect of the tubular pile is studied. The relationship between plastic zone, the limit expansion pressure, the radial stresses and the parameter b is also obtained. The results show that the radius of plastic zone is decreased and the limit expansion pressure is increased, at the same radius, the radial stress is also increased, because of the effect of intermediate principal stress.