Papers by Author: Qing Hua Kong

Abstract: With the development of economic globalization, the union enterprises under the circumstance of inter-industry, inter-regional, inter-national have been making rapid development, which requires that the products R & D need implementing in the distributed heterogeneous environment. Modularity is the foundation of product collaborative design (PCD), and the decomposed modules are vital to improve the efficiency and performance of PCD. To meet the modularity requirements of PCD in the distributed heterogeneous environment, a new method of decomposition-based modularity for PCD is presented based on the combination of the heuristic analysis and the quantitative optimization. Firstly, on the basis of the incidence matrix of sub-task, the mathematic model based on multi-objective optimization is established in order to maximize the module cohesion degree and minimize the module coupling degree, while considering the module executable degree as the restrictions. Secondly, the mathematic model is optimized and simulated by the modified PSO, and the optimized modules are obtained. Finally, the rationality and effectiveness of this methodology is proved in an instance of collaborative design related to automobile body.

Abstract: Experimental researches on material removal rate and surface roughness of Al2O3 engineering ceramic guide-pulley lapping were carried out using W20 and W5 fixed oilstones by self-developed ultrasonic lapping tool both with and without ultrasonic assistance. Experimental results show that lapping speed, lapping pressure and grain size produce different effects on the lapped surface roughness and material removal rate. The material removal rate in ultrasonic lapping process is two times as large as that in traditional lapping, and the ground surface roughness is superior to that in common machining method. The material removal rate increases along with the average diameter of grains and the lapping speed both in ultrasonic lapping and traditional lapping. In traditional lapping process the material removal rate becomes bigger along with the lapping force, while in ultrasonic lapping it gets the optimal value with the lapping force 450N. The value of lapped surface roughness increases along with the lapping speed in traditional lapping, on the contrary it decreases contrast to the lapping speed until 250rpm in the ultrasonic lapping. The value of traditionally lapped surface roughness decreases contrast to the lapping force, whereas it achieves the minimum with the lapping force 450N with ultrasonic assistance.