Advanced Materials Research Vols. 189-193

Abstract: The plate’s mechanical behavior of three-roller plate bending machine had been analyzed in case of upper roller feeding based on ANSYS. Strain and stress distribution of the plate and its changes are gained. The influence of upper roller’s feeding location and bending velocity to bending process are researched. The results are valuable to bending process optimization and practical technique of plate bending.

Abstract: Taking an aluminum tank semitrailer as an example, this essay aim to analyze the strength and stiffness of the tank semitrailer and obtain stress and strain characteristics under different conditions on the basis of a finite element model, by using the finite element analysis software. By carrying on modal analysis in different work conditions, the essay gets the dynamic performance parameters of the tank. The results show that the tank fully meets the requirements of using, and the performance parameters of the tank will be foundation for the optimization.

Abstract: On the basis of thermal error experiment in CNC, the paper reaches a conclusion that at different sampling time, the thermal error model is different from each other. Therefore, this paper proposes a Stepped Approximation Modeling(SAM) Method on thermal error by improving the Multivariable Regression Analysis Modeling Method. The model examples are calculated and compared with presented experiments data. The results show that the SAM has a high accuracy in the thermal error modeling of CNC.

Abstract: The district collaborative design is an advanced design organization mode. The problem of definition and expression of correlation in collaborative design is aimed. The organization characteristics are analyzed based on district collaborative design space. The connection relationship acyclic graph which includes connection semantics is achieved, and the relationship specialty and connection mode are explained. The algorithm is proposed to solve correlation for district collaborative design by use of correlation information model, and the correlation management model based on PDM is illustrated. Finally, a case study is conducted to prove these theory and method

Abstract: As a universal finite element method commercial software, ABAQUS has been widely used in scientific research and engineering applications. However, convergence difficulties are familiar issues while carrying out damage and fracture analysis. Several methods, which are helpful to avoid these convergence problems, are presented in this paper. Baseline simulations about damage initiation and propagation in composites indicate that a larger value of viscous regularization causes the peak of the reaction force to be higher. A smaller viscosity parameter is better than bigger one. Other advanced techniques, include using automatic stabilization and customized general solution controls, are adoptable to improve convergence in ABAQUS/Standard analysis. The results of the paper are expected to provide guidance for the new user of ABAQUS.

Abstract: The key geometrical parameters of twist drills that had a great effect on the drilling performance of stainless steel were studied by Pro/E and DEFORM-3D softwares. The influence of chisel edge and tip angle of twist drill on the drilling force, torque and tool wear in the drilling process was researched, and meantime the effects were introduced by shortened the chisel edge length or adopted S-shape helical drill points as well. The tip angle of drill bit that affected the main cutting edge length, the cutting load on unit length, the proportion between cutting width and cutting thickness in the cutting lay, the cutting force, the torque, the chip formation and chip removal was introduced in detail. The choice of tip angle of twist drill was introduced. In drilling, it has important instructional significance for improvement of life of drill bit, advancement of productivity of drilling and processing quality of hole.

Abstract: Based on the continuum theory, combined with the characteristics of metal injection molding, constructs assumptions and control equation in the die filling process of MIM.With the FLOTRAN hydro-analysis module of ANSYS software, the melt’s velocity ,temperature and pressure fields during injection molding were simulated and compared for different sizes of circular section runners,and discussed the influences between different diameter runners and injection pressure on the flow behavior of melt. The simulation provided theoretical guidance for the design and selection of mold runner in the production.

Abstract: A three dimensional fully thermal-mechanical coupled finite element model had been presented to simulate and analyze the cutting temperature for high speed milling of TiAl6V4 titanium alloy. The temperature distribution induced in the tool and the workpiece was predicted. The effects of the milling speed and radial depth of cut on the maximum cutting temperature in the tool was investigated. The results show that only a rising of temperature in the lamella of the machined surface is influenced by the milling heat. The maximum temperature in the tool increases with increasing radial depth of cut and milling speed which value is 310°C at a speed of 60 m/min and increases to 740°C at 400m/min. The maximum temperature is only effective on a concentrated area at the cutting edge and the location of the maximum temperature moves away from the tool tip for higher radial depths of milling. The predicted temperature distribution during the cutting process is consistent with the experimental results given in the literature. The results obtained from this study provide a fundamental understanding the process mechanics of HSM of titanium alloys.

Abstract: Fatigue failure is the most common failure mode of boring bar in the deep-hole boring processing system. For solving the problem of fatigue failure on boring bar, the new fatigue strength criterion of boring bar is proposed considering the working state including internal and external cutting fluid vortex, linear crack of the across-section, and the maximum bending - torsion coupled stress of boring bar. Firstly, approximate calculation formula of the maximum bending stress was derived considering internal and external cutting fluid coupled effect induced vortex motion. Secondly, near the region of crack tip, the maximum shearing stress was studied when the failure modes of boring bar was considered to linear crack on its cross-section. Finally, the new fatigue strength criterion was established based on bending-torsion combination alternating stress fatigue strength theory. An example calculation in practice showed that if fatigue strength of boring bar is satisfied to the new fatigue strength criterion, its static strength must be satisfied. The new fatigue strength criterion can be used in analyzing the boring bar’s fatigue strength on both complicated working conditions and also single working conditions. The mechanism of failure and destruction of boring bar on BTA deep hole drilling in generally actual working conditions were studied in this paper which are helpful to promote the service life cycle of boring bar in practice. Some rules are also derived to assess the dynamic performance of working boring bar, which structure parameters will be selected reasonably according to it.

Abstract: In the thermal design of embedded multi-chip module (MCM), the placement of chips has a significant effect on temperature field distributing, thus influences the reliability of the embedded MCM. The thermal placement optimization of chips in embedded MCM was studied in this paper, the goal of this work is to decrease temperature and achieve uniform thermal field distribution within embedded MCM. By using ANSYS the finite element analysis model of embedded MCM was developed, the temperature field distributing was calculated. Based on genetic algorithms, chips placement optimization algorithm of embedded MCM was proposed and the optimization chips placement of embedded MCM was achieved by corresponding optimization program. To demonstrate the effectiveness of the obtained optimization chips placement, finite element analysis (FEA) was carried out to assess the thermal field distribution of the optimization chips placement in embedded MCM by using ANSYS. The result shows that without chips placement optimizing the maximum temperature and temperature difference in embedded MCM model are 87.963°C and 2.189°C respectively, by using chips placement optimization algorithm the maximum temperature drop than the original 0.583°C and the temperature difference is only 0.694°C . It turns out that the chip placement optimization approach proposed in this work can be effective in providing thermal optimal design of chip placement in embedded MCM.