Applied Mechanics and Materials Vols. 101-102

Abstract: Due to the difficulty of real-time directly measuring the surface roughness of workpiece, on-line control of grinding quality remains a challenging problem. In this paper, surface roughness of slender shaft during grinding is predicted by using multi-sensor data fusion. Location of the grinding point along the workpiece axis is measured by a grating ruler while an eddy sensor mounted on the machined body provides the workpiece vibration information. The data from these sensors fuse to give an estimation of the workpiece surface roughness. Grinding experiments were carried out to validate this method and the results indicate that the prediction error of Ra is not over 0.1 um for the given setup.

Abstract: Raster image processor is decisive in modern digital printing machines. Three random number generators were examined for their applicabilities to raster image processor. Results show that random number generator should be carefully selected in terms of the screen cell size adopted: linear congruential generator (LCG) is the best for the screen cell size of 8 × 8 or 16 × 16; multiplicative congruential generator (MCG) is most desirable when the screen cell size equals to 6 × 6 or 12 × 12; in the case of 24 × 24 screen cell size, either LCG or MCG is optimum. The workflow of raster image processor was optimized according to our results. These findings are helpful to improve the performance of digital press that is equipped with raster image processor.

Abstract: The wood-plastic structural plates, which were made of polyethylene (PE) and poplar powder, were used in decking as a structural material. It is of great significance to analyze the material reliability for the safety in service. In this paper, the modulus of elasticity and static bending strength of specimens were obtained through test, the first order second moment method (FOSM) was used to analyze the reliability of the wood-plastic structural plates. The result showed that the wood-plastic structural plates have a better reliability, and the reliability of the wood-plastic structural plates was related to the thickness of the specimens.

Abstract: Wood-plastic composites (WPC) , which were made of virgin high-density polyethylene (HDPE) with poplar fibers as filler, were measured by three vibration nondestructive testing (NDT) methods. The values of dynamic Young’s modulus of specimens were measured by different vibration NDT methods, and the values of static bending modulus of elasticity (MOE) were also determined by three point bending test according to ASTM D790-03. The paper analyzed the variability of the dynamic young’s modulus of WPC based on virgin HDPE obtained with different NDT methods, and the correlativity was also estimated between the dynamic Young’s modulus and the static MOE of WPC based on virgin HDPE. These results suggest that WPC can be made of virgin HDPE, and the NDT methods are appropriate to estimate the dynamic Young’s modulus of WPC based on virgin HDPE.

Abstract: The force generated in and required for the sealing process of the first seal of elliptical cans was analyzed based on the energy conservation theory, corresponding formulas describing the sealing-force were derived, and the factors affecting the sealing-force were discussed. This provides a theoretical basis for the design and optimization of the roller curve as well as for further study and calculation of forces in the sealing process of various abnormally shaped cans.

Abstract: Repetitive impact during highway and railway transportation has potential and severe harm for the product with fragile or damageable component. The radiogram belongs to a typical electronic product with panel and box structure, and occurs with the falling down of loudspeaker contacted on the top box, the failure of electronic components, and the fracture of outside box during transportation and storage. So the main feature of this article is the analysis on the natural vibration property, and the evaluation on the drop shock property including amplification factor and relevant curves under nine kinds of repetitive impact with different impact duration and drop height. The results show that the amplification factor markedly rise while the impact duration 2.02ms (nearly causing the resonance of radiogram), the repetitive drop shock may bring more serious damage than single impact load, so the case should be paid attention for the design of package cushioning.

Abstract: The parameterized drafting technology an database, which is used in diagram drafting of centrifugal fan, is introduced in this paper. The parameterized drafting system for main parts of centrifugal fan is developed by VBA under the circumstances of AutoCAD 2000. The paper introduced the realizing process of drafting principle and system function in detail.

Abstract: Through the test of mechanical properties of the straw-biodegradable tableware, the relationship between performance and processing technology was analyzed and the optimal solution was obtained. And using finite element analysis software, the internal stress distribution under the specific load was obtained based on mechanical properties, more valuable reference method about tableware design was provided through studying the changing intensity.

Abstract: The experiment on slender shaft open-cycle belt grinding process is conducted in this paper. The research objects are dimensional accuracy and deviation from roundness error, the changes of which are emphasized after the belt grinding. And the factors affecting the working accuracy of the belt grinding are analyzed. Some measures for improving working accuracy of the belt grinding are put forward. Research result shows that by installing a belt grinding device on a lathe to grind the slender shafts can improve the accuracy with high efficiency.

Abstract: Under the condition of large inclined angle, the stability control of hydraulic support was always the challenge for the fully-mechanized mining in large inclined coal seams. Based on the specific geological conditions of 509 coalface with large inclined and high mining in Gaozhuang mine, the model of hydraulic support had been drawn by using SolidWorks software, and the inclination mechanical model of hydraulic support had been established to analyze its inclination stability along coalface. The calculation result shows that when the maximum inclination angle is 31° and the underhand angle is 10°, the minimum support resistance needed to keep the hydraulic support not dumping is 283.59 kN. Meanwhile, the critical support resistance required for the hydraulic support not to dump in inclination direction increases approximately linearly along with the increase of coalface mining height; under the same mining height condition, the critical support resistance increases along with the increase of the inclined angle. Therefore, the selection of the mining height and inclined angle of the coal seam must be considered at the beginning of the hydraulic support design.