Advanced Materials Research Vols. 490-495

Abstract: In this paper, 3D model reconstruction on a denture that has undergone the run-in time is studied, using reverse engineering technique. In the stage of surface data acquisition, since the denture has very complicated and irregular contour, a non-contact mode is preferred. In point cloud data pre-processing, salient outliers are manually removed; Gaussian filter is used for noise suppression; curvature-based sampling is adopted for data reduction. In the model reconstruction stage, the surface reconstruction which is based on enclosed triangular Bezier surface patches is used for it can deal with arbitrary shape contours. Then, hole patching, smoothing and reduction are added for refinement of the surface creation. At last, the errors of the whole reconstruction process are measured and evaluated. The results indicate that our reverse engineering work has good performance, which can bring about comfortableness for the use of future dentures by patients.

Abstract: Dynamic model of nonlinear rotor—bearing system is set up using the modified Capone bearing forces models. And the nonlinear dynamics behavior of unbalanced rotor—bearing systems was studied. The system state trajectories, Poincare maps, are also constructed to analyze the typical dynamic behavior of the system．Through the nonlinear dynamic numerical simulation of the system，the dynamic phenomena of the rotor—bearing system caused by oil film forces are clearly distinct. The computational results show that the rotor speed is one of the most important factors of the system dynamic behavior. It presents a periodic, period-doubling motion, quasi-periodic motion, and abundant nonlinear dynamical behavior with the changes of the speed.

Abstract: Trust chain is fundamental technology of Trusted Computing facing many problems. This paper points out that trust chain is made of two stages, analyses different trust relation building mechanism of two stages, and also thinks and proves that trust loss during trust transitivity process comes from composition loss and so on, describes behavior of trust chain transitivity quantitatively. After discussing key factors affect the trust, this paper defines the general trust transitivity model and trust loss measurement function, and discusses trust loss of Stage1 in TCG.

Abstract: Seeing that the influence quality factors of product lifecycle are multi-object, multi-level, interconnection and interaction, which possess uncertainty and fuzziness obviously, in order to product quality, quality evaluation mathematical model based on Fuzzy Analytical Hierarchy Process (FAHP) and Fuzzy Comprehensive Evaluation (FCE) is proposed to evaluate product quality. This method introduced the triangular fuzzy number to represent experts’ judgment information of product quality and used the AHP to rank these influence quality factors. At last, FCE is used to make the results of product quality evaluation more scientific and effective. The product of some Heavy Machinery Enterprise (coal grinding mill) is introduced as an example to demonstrate the rationality and validity of the method.

Abstract: The accuracy of TSP in tunnel geological prediction system is restricted to the conditions of construction site. In order to improve the accuracy of the prediction result, it is necessary to improve the collection accuracy. This article is for the angle to improvement of focal points, charging structure, optimizing the explosive charge, improvement of the detection holes for receiving conditions to improve the data precision. So that the focal point detonating degree guarantees at a higher level, the accuracy of the data is relatively well, and the interpretation results are more accurate.

Abstract: Due to film thickness is one of important parameters which has great influence on the performance of mechanical seal, the accuracy of thickness measurement is significant on mechanical seal condition monitoring and performance study. Some limitations were faced when common sensors were used under water of seal face. As new type sensor, FOS has many advantages such as smaller diameter, higher sensitivity, better anti-jamming ability, larger applicable scope than common sensors. In this paper, an enclosed and rotatable calibration test-bed was designed to imitate seal structure by which the feasibility and specifications of FOS application to measuring the seal film thickness had been discussed

Abstract: In recent years, there were frequent earthquakes happening in China. These earthquakes have give rise to a high degree of casualties. However, compared with Japan in which the number of the earthquakes is the highest in the world, China's earthquake-proofing legal standards, requirements on the earthquake-proofing designs and the rate of the earthquake-proofing technologies as well as understanding of the structure of the building are not under the immature state at the present time.

Abstract: For some old diesel generator sets, interactive power oscillation often occurs in the parallel operation, owing to interference of oil supply. Through the analysis on the generator rotor equation, the paper first determines the cause of power change, and then uses control methods to eliminate the power interact oscillations based on actual conditions, and finally uses Matlab simulation to verify effectiveness of control methods

Abstract: Formability of the corner in the deep drawing of box-shaped parts was studied. The forming of box-shaped parts was simulated through numerical simulation software DYNAFORM from the different die radius size of shoulders and corners, the different BHF of straight and curved edges and different materials, etc.. The results shows that, the forming limit height of box-shaped parts increases with the larger the die radius of shoulders and corners, and forming limit height of SS304 in the materials studied is the highest, because it has larger yield strength; If the BHF of straight and curved edges has the constant size, the forming limit height of box-shaped parts will be lower when the BHF increases, while forming limit has a clear upward trend as blank holder force increases in the deep drawing processes which accords with the change law of resistance during the dislocation movement.

Abstract: Based on the analysis of the common NN-type involute planetary gear reducer with small tooth number difference, this paper replaced the traditional eccentric axle sleeve with double eccentric crankshaft, so as to simplify the structure of involute planetary gear reducer with small tooth number difference; and then used closed graph to select the modification coefficients of the internal gear pairs thereby accomplishing the design of the new type reducer; Finally, used ANSYS Workbench software to analyze the modal of 3D virtual prototype, and arrived at a realized conclusion :the inherent frequency of the system is much higher than the input frequency, so resonance will not occur.