Advanced Materials Research Vols. 148-149

Abstract: A 5-axis machining method of Non-Uniform Rational B-Spline (NURBS) surface has been proposed in this paper. With the local curvature and the machining error, the step-size was calculated to get the parameter of the next Cutter-Contacting (CC) point. With the method of coordinate transformation, effective machining radius of a flat-end cutter had been deduced and the step-over formed by two adjacent CC paths were implemented. The parameter increment along the CC path interval direction was calculated by using geometric analysis of the local area of CC point. Finally, once all of CC points on the NURBS surface had been obtained, the CC paths for 5-axis surface milling were generated.

Abstract: As one kind of railroad tracks, the slab track already widely applied in the high-speed railroad. In order to satisfy the very high-speed-railroad security and the comfortable need, the request of slab track's ultimate subsidence is very strict during construction and operation. Examined in this paper is the roadbed subsidence rule of Wuhan – Guangzhou railway passenger special line in China. The site observation of roadbed subsidence deformation is utilized and has drawn up the settling curve. Goes a step further, based on the numerical calculus method and the forecast assessment, the roadbed subsidence rule of different ground reinforcement processing has been represented. It is shown that the ultimate subsidence satisfied the request of design and the subsidence deformation of CFG pile compound ground was smaller than that of other ground. These conclusions provide uses for reference importantly to guarantee the quality of slab track on railway passenger special line under construction.

Abstract: A three-dimensiona1 nonlinear finite element analysis(FEA) mode1 of radial tire，which includes the materia1 nonlinearity and the geometric nonlinearity of the 1arge deformation, is established to analyze the effective factors on the wear resistance of 195/60R14 tire．It shows that the distribution of the friction force in the ground-contact area gradually changs from greater inside and smaller outside to greater outside and smaller inside with the increase of the 1oad of tire. It also shows that the maximum friction force, which decreases at first and increases later as the angle of belt cord increases, occurs in the shoulder area. The static friction force in ground-contact area is symmetrically distributed. On the one hand, the over inflation pressure leads to the increase of the maximum friction force resulting in the premature wear in the middle of crown under the same load. On the other hand, the under inflation pressure leads to the phenomena of bridge effect, which is resulted in the uneven wear in the tread．

Abstract: Aim at the problem of Ansys/LS-DYNA software simulating in the shaped charge modeling, this paper studies the influence of calculating gridding size on the multimode penetrator forming. It can be found that when the gridding size is 0.028 times the charge caliber or less, the formation of penetrator can be good with the trail result. It obtained the change curve of the model nodes and the calculating time of certain computer with the size of gridding. When the gridding size is from 0.022 to 0.028 times the charge caliber, the model nodes diminish 30.8%, and the calculating time decreases 42.9%. It obtains the effects of calculating gridding size on the multimode penetrator formation parameters, such as velocity and length-diameter ratio. The simulation results were validated through X-ray imaging experimentation. Both results are in good agreement.

Abstract: In this paper, a novel algorithm called CIPSO for short based on particle optimization algorithm(PSO) and Chaos optimization Algorithm(COA) is presented to solve traveling salesman problem(TSP). We propose some new operators to solve the difficulties of implementing PSO into solving this discrete problem based on the special fitness landscape of TSP. Meanwhile embedded with chaos theory it can enhance particles’ global searching ability so as not to converge to the local optimal solution too quickly, and the introduction of information intercourse can enhance thire local searching ability. Comparing to SA, GA, ACS and so on, this new algorithm shows its validity and satisfactory effect on several benchmark test problems.

Abstract: Based on the data obtained from the perpendicular experiment of laser surface hardening on HT150 cylinder liner of a certain motor engine, a Radial Basis Function (RBF) neural network prediction model of laser surface hardening index about HT150 cylinder liner is established by Matlab neural network toolbox in this paper. The parameters of input layer are affirmed by analyzing influential factors of the hardened index ,and the best form of the network is affirmed by selecting suitable spread in function-newrb( ),and as a result, the prediction accuracy and the adaptability of the network are improved. The result of testing the model indicates that the model based on RBF neural network has a good generalizing capability. Compared with traditional Back-Propagation Network (BP network), the result indicates that RBF has better accuracy and adaptability.