Abstract: Based on BP neural network, this paper had a prediction on ultimate bearing capacity of prestressed pipe pile. Taking pile diameter, effective pile length, ultimate average value of friction standard value, ultimate average value of end resistance standard value as influences factors, the prediction model of pile bearing capacity based on BP neural network was obtained. It was found that, the average value of absolute value for the relative error of fitting value of pile bearing capacity compared with the observed value for 70 groups of independent variables training BP neural network model was 3.1498%; And the average value of absolute value for the relative error of prediction value of pile bearing capacity compared with the observed value for 10 groups of independent variables validating BP neural network model was 3.50126% whose precision was better than ANFIS’5.32293%. The following conclusion can be drawn that, the prediction model of ultimate bearing capacity of prestressed pipe pile based on BP neural network is feasible.
Abstract: A method for accurate registration on point clouds is presented in the paper. Manual alignment or the use of landmarks is avoided in the process of multi-view point clouds. Firstly, the differential geometric information is extracted from the point clouds. The extended Gaussian sphere and combination features are used to define the corresponding points of crude alignment. Secondly, the optimal algorithm，the point-to-point Iterated Closest Point, is applied to the accurate registration on point clouds. Thus, the complete point cloud can be obtained in the method.
Abstract: A new method is proposed for the linear complementarity problem (LCP). Firstly we formulate the LCP into a multiobjective optimization problem (MOP), and study the relations between the efficient solution of MOP and optimal solution of LCP. Based on the efficient solution of MOP, we define zero-efficient solution. Then we indicate that zero-efficient solution of the MOP is also the solution to the LCP. Finally some standard LCP examples are respectively transformed into MOP and solved by minimax method. Numerical results indicate that the proposed method is effective.
Abstract: The filling capability of forging die is important to design forging die and it exerts a decisive influence to the quality and life of die. Due to the deficiency of the filling capability, and taking Ti3Al alloy as the research object, at the same height of reducing, work-piece dimensions as the control objective, the finite element numerical simulation method was used to simulate the hot compression of Ti3Al alloy with DEFORM-3D. This test simulated the process of hot compression, analyzed the hot deforming behavior of the stuff and discussed the effect of work-piece dimension on the variety and distribution of stress and strain.
Abstract: The kinematics simulation of 6-PURU parallel mechanism was made based on dynamics simulation analysis software ADAMS, and the simulation method and steps were introduced too. Using UG to establish 6-PURU parallel mechanism soiled model, and the geometry model parasolid format was payloaded to ADAMS environment and established virtual prototyping model, by added some drivers and SPLINE curves, the model was conversed with positive kinematics simulation. This method avoided to establish and solve complex kinematics equations, simplified the design and development work of the parallel robot, but also provided theoretical basis for adjustment and control of prototype.
Abstract: In this paper, taking the twin tripod sliding universal joint as three-dimensional solid model, adding various kinematic pairs and motion drivers between kinds of components, using multi-body dynamics software ADAMS that is popular at present, carrying out the dynamic simulation, contrast with or without friction force of the coupling’s movement under the action of those forces, such as the force on the slider, ball head, the journal, and so on. Finally, we obtained the movement rules of the couplings under or without those forces and some qualitative theories, which provided theoretical basis and reference for the subsequent design and research for couplings.
Abstract: By the combination of orthogonal experiments and moldflow simulation analysis, the warpage of a thin-wall injection molded parts is analyzed under the combined effects of multi-molding process parameters. By this method, it can gain the experiment data which can basically reflect the overall situation using fewer number of simulation analysis. In addition, the effects degree of different molding process parameters for warpage are researched, and the optimized parameter combination is obtained. It can avoid the one-sidedness of individual analysis of the various factors and solve the unreasonable appearance of process parameter settings. With the help of results, it can fasten the mold developing schedule, thus shorten the cycle of product development, and improve the quality of products and the competitive ability of enterprise.
Abstract: This paper introduced the characteristics of eccentric multi-axes rectangular shield machine and made comparisons to traditional earth pressure balance shield machine. And introduced structure form of eccentric multi-axes, and carried out calculation of cutter head driving. The author completed the finite element calculation of eccentric axis with COSMOS Works, the results of calculation shows that maximum stress occurs at the place at gear keyway of eccentric shaft, but the eccentric shaft can satisfy the requirements in shield design according to big load in cutting soil. Finally, the eccentric shaft was applied in several engineering cases without any structural problems.
Abstract: The carrier frame is the installation base of ROV’s each subsystem and the main force component when lifted and recycled. Its research is designed to ensure sufficient strength, stiffness and weight as small as possible.In order to seek the optimal design proposal in initial stage of design, the finite element analysis and size optimization of one under researching ROV’s carrier frame are carried out.According to the result of optimization, the structural mechanics performance after optimization could basically remain unchanged, also the weight of the structural reduces 5.8 percent.
Abstract: In the distance learning of the courses of Machine Parts and Design, the hypothesized experiment through internet is a kind of the significance teaching method. At present, multimedia, network technologies are extremely mature. Using the internet technology to realize the course learning can help the students to master the principle of chain drive easily. The key problem to realize the hypothesized experiment on the net is how to carry on the simulation of machine parts or components using the computer software. The realization method of the hypothesized simulation of chain drive is introduced in this paper based on MSC. Visual Nastran 4D software.