Advanced Materials Research Vols. 291-294

Abstract: Structural analysis software for amorphous alloy has been developed. The structure factor, distribution function, the first coordination number, the first coordination radius, the correlation radius, the atomic number of cluster and the atomic average density of amorphous alloy can be gotten with this software. This software’s runtime stability and calculated accuracy was verified by its practical application. Structure of amorphous Zr₄₁Ti₁₄Ni₁₀Cu_12.5Be_22.5 alloy was exactly analyzed using this software, which proved that the design of the software is precise and the calculation is exact.

Abstract: Splat deposition is an important part influencing coating quality in plasma spray forming. Flatten behavior of a single Ni droplet falling on a smooth substrate is evaluated by numerical simulation of ANSYS software, this paper meanwhile researches a single Ni particle deposition in the surface of flattened Al₂O₃ sheet and thin Al particles, the impact factors of particles flattening and the mechanism of the interaction between particles are also studied. The results have benefit to improving the coating porosity and bond strength between particles.

Abstract: This paper studies the thermal interaction of Ni particle and Al particle setting in the carbon steel surface using ANSYS software by finite element numerical simulation. It highlights the temperature-time change of feature points that are at different locations of flattened particles and substrate, and micro-contact heat transfer of particle and substrate surface is also analyzed. The results help to study residual stress distribution of a splat particle in the plasma spray forming, which further provide an important basis for improving the quality of the coating.

Abstract: The characteristics of air flow inside the inner channel of a Hema-type ATY(Air-Textured Yarn) nozzle were simulated based on the geometrical model of the inner channel built up usingPRO/E and the turbulent air-jet with a standard k-ε model simulated using Fluent．The simulation revealed that the ideal air in equivalent temperature came to channel while the flow pressure reached to the minimum．The results visually demonstrated the flow field of the inner channel of Hema-type ATY nozzle．And it could be a valuable reference for optimizing parameter on the Hema-type ATY nozzle.

Abstract: In CNC machining, various errors, which caused by the cutting process and the structure of the machine tool, affect the machining accuracy of the machined parts. To analyze the relationship among the cutting force induced error, the thermal deformation, and the tool wear induced error, the empirical formula is employed in this study. The result shows that the cutting force is the main factor which affects the error distribution of the machined parts; the thermal deformation and the tool wear induced error change the error distribution. Furthermore, all the errors are coupling each other. To improve the accuracy of the machined parts, a pre-compensation method is proposed. To achieve the real-time error compensation, an application is designed to calculate the coupling error and to generate the NC code. Using the pre-compensation method, the maximum error is reduced from 0.015 mm to 0.002 mm. The error is compensated by 86.7% compared with no compensation.

Abstract: Numerical simulation based on finite element modeling is used widely for the prediction of welding residual stress and distortion. Considering this method, the accuracy of the ultimate result of the residual stress and distortion field is depended greatly on the accuracy of the welding temperature field. The APDL languages of ANSYS procedure was used in this study. In order to model the addition of the filler to the weld, element birth and death technology was selected. It well performed to simulate the moving of the heat source and the process of transient thermal convection. The results show that the change process and the distribution of the welding temperature field agree well with the weld reality.

Abstract: Gas bubbles entrapped in polymer intermediate layer often lead to voids which are severe defects of adhesive bonding qualities. Although the empirical method had been used for a long time to eliminate the bubbles, theoretic analysis considering the bubble behavior during bonding process is more preferable because of the better universality. The interrelationships between processing parameters and bubble deformation were investigated. A theoretic model describing those interrelationships was developed reasonably using gas diffusion theory to predict the bubble behavior. The mathematic equations of this model were deduced and the solution was obtained with some proper simplifications. Experiments under different conditions were carried out and the experimental results were contrasted with the theoretical predictions. It was obvious that when choosing temperatures and pressures carefully, the model could predict the bubble behavior accurately.

Abstract: According to the geometrical characteristic of workpiece and groove in the stretch reducing rolling process, three-dimensional elastic-plastic finite-element analysis model was established to simulate the metal deformation, the regularities of distribution of wall thickness of transverse direction longitudinal direction were investigated. The analysis was verified by comparing finite element analysis results with on-line measurements. The length of crop ends was determined as well as product bore polygonization. The study provides the foundation for analyzing product defeat and instructing technological design.

Abstract: To build a dynamic vehicle model is the most important work in the field of digital virtual prototyping technology for studying on its handing and stability. A 54 degrees of freedom multi-body vehicle model with tire, suspension and steering was established in SimulationX software. Time domain response under steering wheel step input and frequency response under steering wheel sinusoidal input were obtained, the changing trend of indicators with different speeds was presented, the handing and stability of vehicle model was evaluated, also the impact of caster angle and kingpin inclination to handing and stability was analyzed. The simulation results were consistent with theoretical analysis and actual situation.

Abstract: The eccentricity coextrusion flow of polymer melt was analyzed based on finite element simulations. Such simulated results as the fields of flow velocity, pressure and shear stress were obtained. Through the analysis of the results, the mechanism of the column interface forming in the axis-symmetry coextrusion flow path was obtained. For the coextrusion flow, if the low viscosity polymer flows near the die wall, the flow would be steady. Whereas, if the polymer with low viscosity is in the core and the high viscosity polymer at the outer region, Which is disadvantage in terms of energy, and the instability flow would occur. This is also accord with the least energy consume theory.