Advanced Materials Research Vols. 479-481

Abstract: The distribution of hot runner temperature field in injection moulds affects both the plastic melt performance and the quality of plastics and production efficiency．The establishment of mathematical model for the temperature field and the computing way were analyzed．The numerical analysis on the temperature field was made on computer, and a feasible mathematical model was achieved．Then a practical example was described．The study provides scientific and theoretical guide for the accurate control hot runner system temperature

Abstract: Low pressure die casting (LPDC) process of a copper-alloy tap was simulated by the finite element software ProCAST. The casting defect and its reason were analyzed. The optimized design was discussed and the simulation was validated against the low pressure die casting experiment. Results showed that the main defect is misrun and its reason is that the melt solidifies too fast. It’s well solved by increasing the wall thickness of the relational pipe properly. The result agrees with the experiment.

Abstract: The virtual prototyping model of large erecting system is established by means of ADAMS and AMESim software. Based on the theory of multi-rigid body dynamic, the topology description of erecting system is given. Dynamics analysis model of large erecting system is built in ADAMS software, and mechanics character is given through the analysis of the erecting system. The simulation model of hydraulic system is built using AMESim software. Collaborative simulation based on the interfaces of ADAMS and AMESim is discussed, and the dynamic characteristic of the erecting system is simulated based on the interfaces of ADAMS and AMESim. Some simulation results are given to demonstrate the validity of the proposed model. This method provides a new approach for the modeling and simulation of electro-mechanical systems.

Abstract: Analysis had been carried out, based on the three-dimensional transient viscous turbulent calculation of a Francis turbine full flow field, the complete cavitations model and the two-phase mixture flow model were combined during the calculation, more accurate numerical solution had been obtained. According to the simulation results, the site and extent of cavitations in the turbine flow were reflected within the specific conditions, and were more consistent with the cavitations phenomenon observed in the model experiment, also provided a reference for the more in-depth research.

Abstract: Based on the research of Engineering geological characteristics，formation mechanism，failure mode and later change trend of Zigui county Bazimen landslide in Three gorges reservoir area,we put forward the warning construction scheme of landslide monitoring, introduce the layout of monitoring network and the construction technical requirements of all kinds of deformation monitoring,it can be refered to by other landslide monitoring projects.

Abstract: By virtue of Pro/Engineer, the parts of Roofbolter luffing mechanism are established, and the virtual assembly models are completed. Then the models are imported into virtual prototype software ADAMS using the technology of software interface. In the working environment, the virtual prototype of roofbolter are constructed after adding reasonable constraint and drive, also through setting motion function for the hydraulic cylinder of luffing mechanism, the kinematic simulation is conducted, and the results are analyzed and the rationality is verified, also it provides theory basis for the subsequent improvement and optimization.

Abstract: This paper used finite element method to analyze thermal characteristics of numerical control (NC) machine spindle system, and studied the steady temperature field and the transient temperature field of the machine tool and the thermal deformation of the spindle at 3000 rpm. General finite element analysis software ANSYS is used for analysis. Through the analysis of the temperature field and thermal deformation of the spindle system, this paper finally obtained the deformation situation of the spindle system in thermal load. By changing the boundary conditions of the spindle system to analyze the heat distortion of the spindle system and the results showed that assembling a cooling jacket in front of the spindle box can signally reduce the thermal error of the spindle system.

Abstract: Charged air coolers (CAC) are the major components in automotive turbo-charging system. Fin parameters play an important role which affect thermal-hydraulic performances significantly. According to typical fin structures, this paper carried out the matching design of hotside and coldside flow channels in CACs. Based on numerical simulation results, the fluid flow and heat transfer performances of 9 matched CACS were comprehensively evaluated and thus the optimal structure was determined. The results are consistent with engineering practices. This design method can reduce CAC research costs and shorten development period and offer guidance for the designing and manufacturing of CACs.

Abstract: Taking a sedan as the research object, the frontal impact simulation was done. The results showed that the corresponding results of the structure deformation of the body are in agreement with the experimental data. On account of the driving zone and driver survival space that were compressed seriously, some improvements of the front carling were taken in designing. The structural simulation analysis and dummy injury analysis were done to verify the effectiveness of the improved scheme: the peak acceleration of B-Pillar was greatly reduced, the damage value of dummy was significantly reduced, and so greatly improving the car's passive safety.

Abstract: The gravity is a serious problem for the deploying experiments of a large deployable space antenna on the ground. With the increasing trend for much bigger size deployable structures, new ground experiment methods with expected effects or with low cost should be explored. On this special object, we propose several deploying schemes from theoretical design, to practical design and then to actual design on a new folded hoop-rib mesh antenna structure we proposed before. Through the fundamental processes from theoretical analyses to actual experiments, it shows that the fairly complex mechanism can be deployed successfully, which reveals that the new deploying antenna structure design is feasible and reasonable.