Abstract: This paper proposes an approach for calculating the transmission ratio of nutation drive based on the working principle of the nutation movements. Then, the analysis of the influences for the nutation angle on the transmission ratio is carried out. The controllable tooth profile modelling for external and internal spiral bevel gears with double circular-arc is proposed. Based on the proposed tooth profile modeling, the three dimensional modeling and virtual assembly of the nutation drive have been further completed. Finally, the kinematical simulation is preceded in the simulating system and the comparative results have been accomplished between the simulation results and the theoretical ones of the transmission ratio.
Abstract: Performance evaluation techniques of manufacturing systems are powerful decision support tools especially at system design stage. In this paper, an approximate technique based on decomposition method is proposed for performance evaluation of serial homogeneous transfer lines with unreliable machines and finite transfer-delay buffers. The characteristic of transfer-delay buffers means that it takes some transit time to transfer the parts through buffers, which increases the complexity of transfer lines. In order to address the problem, we firstly transform the initial transfer line into an equivalent transfer line, a serial non-homogeneous transfer line with unreliable machines and finite buffers. Then another transformation which replaces the equivalent line by an approximate homogeneous line is introduced. Finally, decomposition method is used to deal with the approximate model. The accuracy and efficiency of the method are validated by simulation results.
Abstract: For a class of three-loop architecture motion control system, two-stage close-loop identification is introduced to estimate the control plant and thus to tune the velocity controller. Based on the estimated model, PID position controller with derivative filter is proposed using pole-zero cancellation and pole assignment. Feed-forward compensators such as Velocity and Acceleration Feed-forward Controller (VAFC), Zero Phase Error Tracking Controller (ZPETC), Zero Magnitude Error Tracking controller (ZMETC) are introduced as well, and their effects are compared.
Abstract: In view of the limitation of trial cutting or manual inspection of the process planning validation of conventional numerical control, a new method of planning process simulation based on virtual reality was proposed. Firstly, the structure and implementation scheme of simulation system were given, and the simulation platform was established. Then, the movement behavior of machine tool was analyzed in details, an event handle model based on message response mechanism was proposed. Take tool change for example, the behavior module and the motion mode of related components were described. Researched and inferred the solving process of the curved surface of tool sweeping. The NC code compiler and cutting process simulation were expounded. Finally, the system was realized by means of using Visual C++6.0, OpenGL, Virtools and so on, It could verify the rationality of process planning and achieve the accurate assess.
Abstract: With a synthetic study on the mechanical properties and deformability of TWBs, and an advanced mechanical analysis of weld-line movement, the theoretic basis for the whole forming and redesign of a complicated component of auto body (body side-inner panel) was achieved. Then a preliminary redesign was conducted with the selection and collocation of parent metal, the layout of the welding position, and the design of integral forming drawing taken into consideration. Thereafter, by simulation forming and parametric optimization, the redesign of the component was completed and its stamping forming technology was greatly improved.
Abstract: In the present work, a finite difference model (FDM) is built to predict the transient temperature field of the aluminum billet in the gradient cooling process. The billet is divided in 5 segments, each of which is corresponding with one water cooling ring, and all of which are water-cooled for different times respectively in order to obtain the target temperature gradient. On the following air cooling stage, the temperature of the outer layers, especially the surface, rises first, then falls slowly. With the rising of the surface temperature, the temperature deviation from the center to the surface is narrowed intensively. In comparison with the commercial finite element method (FEM) software, Deform 3D, the FDM model gets nearly the same prediction results as FEM simulation does.
Abstract: As the capacity and thermal parameters of turbine generator become larger and higher, the strength design plays increasingly important part in manufacturing process while the traditional strength check method based on the nominal stress which is modified by the stress concentration factor has many disadvantages. The paper proposed Finite Element Analysis (FEA) to analyze the local stress which is more accurate and convenient to seek the dangerous failure point. The possible running conditions which maybe encountered in field are needed to be adequately considered in design process. Two phase short circuit which is the unavoidable condition in the unit’s running porcess plays significant impact on the shafts strength life and the unit’s life-cycle. The paper analyzes the fatigue evaluation of two phase short circuit to enhance the design reasonability as a typical case study. Using FEA and fatigue evaluation methods, more details of the shafts structures and the running processes are taken into accounts which make the dseign process more reliable.
Abstract: The function integration, process integration and information integration of the manufacturing system are all in need of the support of the personnel integration. But the complicated relationship among personnel has caused difficulties in personnel integration. In order to analyze the correlation between personnel in manufacturing system, an analysis method based on the relation degree matrix was proposed, meanwhile the personnel in manufacturing system was classified according to the product life cycle(PLC). The above work has paved the path for the further development of a kind of operation mode for personnel integration in manufacturing system based on PLC (MOPI). The mode is composed of four layers, which are the target layer, the PLC layer, the personnel layer, and the supporting system layer. The above mode was implemented in a local manufacturing enterprise, and positive application effect was achieved.
Abstract: Take a certain suspension system of forging manipulator as research object, mechanical system sub-model and hydraulic control system sub-model of suspension system were respectively built by using Pro/E, Mechanism/Pro, ADAMS and AMESim software, and the whole virtual prototype model of suspension system contains mechanical and hydraulic system sub-model was connected by interface module of software collaboration. Based on integrated features of virtual prototype technology, the dynamic and static characteristics of suspension system were researched by the method of multi-field co-simulation and software collaboration. The results can provide certain theoretical significance for designing suspension system of forging manipulator.
Abstract: A fully transient method for the simulation of the coupled plastic part and mold temperature in the filling stage of Rapid Heat Cycle Molding process was presented. Unlike the constant temperature boundary conditions in conventional injection molding simulation methods, the mold temperature was assumed to be variable in the filling process. The mold temperature in the heating process was first simulated. In the filling process, the flow equations were solved only on the cavity domain, while the energy equations were solved in a coupled manner for the cavity and mold domain at the matrix level. The temperature evolution in a two-dimensional filling process with heated mold was simulated. Numerical results showed that the proposed coupled simulation method provides reliable temperature estimations in mold filling process.