Papers by Author: Xiao Bo Liu

Abstract: Based on the analyses of aluminum melt solidification and heat transfer during the process of twin-roll casting, a coupling mathematical model of thin-gauge high-speed casting was developed, which included the casting roller shell. At the same time, FEM was adopted to solve the coupling model. The temperature field, thermal stress field and strain field of aluminum melt in casting zone were simulated by this model. When the casting velocity is 7m/min, and the thickness of strip is 2 mm, in the melt zone, the temperature of melt decreases rapidly as it approaches the rollers; the surface stress of strip is larger than the central stress; In the liquid zone and mushy zone, thermal stress is relatively small; in rolling zone, thermal stress is much larger than in the former two zones, and gradually increases along exports, then gradually decreases after the peak; the outsurface strain of the casting strip is larger than the inner strain, and the thermal stress gradually increases along exports.

Abstract: As the condition of a certain blade cracked of rotor system of fans, limited short-axletree nonlinear dynamics model is used ,the vibration frequency and nonlinear dynamic stability single-disc rotor is discussed, interior stress distribution and size of rotating shaft after loaded is analyzed concretely by ANSYS software. Through contrast X, Y, X-Y three directions stress distribution of rotating shaft interior, for entity model of near support disc and shaft, it is observed that its field of stress distribution compare dense is near--support field，also stress concentration is relatively bigger after load is added. Meanwhile ANSYS software is used to calculate by simulation this relation of the blade cracking spread width-temporal of four different alloy material and to count the intensity、stress distributing and the axial displacement of the axletree. The best numerical value about elastic modulus and hardness of the material is found by analysis the curve of crackle width- time function.

Abstract: The dynamic evolution of grain growth in the process of aluminum casting and the impact of different casting conditions on the grain growth were simulated by using the Cellular Automation(CA) method in this paper. The simplified binary alloy was used to simulate the growth of the grain in the undercooled melt, Finite Difference Method (FDM) combined with relative motion was used, and dynamic evolution of microstructures in the process of aluminum twin-roll casting was achieved. Visual Fortran programming language was adopted to calculate and realize the image post-processing. based on the growth of the grain in the undercooled melt, the impact of the undercooling triggered by cooling and the casting speed on aluminum strip in the casting process was simulated. The results indicate that, in the condition of a certain nucleation rate, as the cooling intensity increases, bigger the grain is, which provides a basis for optimizing the twin-roll casting process parameters.