Papers by Author: Yan Lin Wang

Abstract: The morphologicalstability of a planar interface with the inclusion of the anisotropic surface tension is studied. The dispersion relation is obtained by means of the multi-variable expansion method. The result shows that the morphological stability of the solidification system in the extremely short wave region depends on the undercooling. As the anisotropic surface tension parameter increases the perturbation growth rate of the interface increases and the solidification system in the extremely short-wave region tends to destabilize.

Abstract: Along with the rapid development of the science and technology, the requirements of microstructure and properties for the bearing steel are more and more strict. The recrystallization behavior of hot deformed austenite in GCr15 bearing steel was systematically studied under the different deformation amount, deformation temperature and dwell time after rolling, the changes of microstructure and recrystallization percentage was analyzed. The research results show that the recrystallization behavior of hot deformed austenite in GCr15 bearing steel is more and more obvious as the deformation amount, deformation temperature and dwell time after rolling increase, the microstructure is more uniform, and the recrystallization percentage increases; When the deformation amount is 20%, the deformation temperature is 850°C and the dwell time after rolling is 10s, the recrystallization percentage is 32.09%, when the deformation amount is 45%, the deformation temperature is 950°C and the dwell time after rolling is 60s, the recrystallization percentage is 64.31%, comparing it to 32.09%, it increases 100.4%.

Abstract: The influence of microstructure in GCr15 bearing steel by the different heat treatment conditions was studied, and the influence regular pattern of recrystallization percentage in GCr15 bearing steel by the different deformation amount, deformation temperature and dwell time after rolling was also analyzed. The research results show that when the deformation temperature and deformation amount under certain conditions, the recrystallization percentage of deformed austenite in GCr15 bearing steel increases as the dwell time after rolling increases, and the austenitic grain is also grow up; The uniformity of deformed austenite organization is influenced greatly by the different deformation amount, deformation temperature and dwell time after rolling, when the deformation temperature is 950 °C, the deformation amount is 45% and the dwell time after rolling is 100 S, the recrystallization percentage can up to 84.57%.

Abstract: Based on the reinforced concrete beam structure bonding with steel plate are consisted of different materials, the finite element model of the reinforced concrete beam structure bonding with steel plate was established using the whole model and the separated model respectively, the deformation, stress, strain and limit load of the reinforced concrete beam structure under the symmetrical concentrated load and the uniformly distributed load were studied using ANSYS. The research results show that the limit load value based on the finite element simulation is basically equal with the experimental value, there has little error between them, but within the scope of control in error, and the limit load under the uniformly distributed load is greater than the symmetrical concentrated load; The results from the whole model and the separated model are basically equal with the experimental results, which show that it’s feasible using the finite element simulation to analyze the reinforced concrete beam structure bonding with steel plate.

Abstract: The centrifugal pump is the common mechanical equipment, which is extensively applied in the water conservancy, ships and other projects, and the blade structure is a very important part in the centrifugal pump. In this paper, the stress distribution and concentration of single blade in the impeller are analyzed under the different pressure field of the blade structure surface, and the fatigue failure of blade is also studied. The research results show that the we can get the stress and strain of the blade accurately and intuitively through the analysis for the blade structure, the stress concentration of the centrifugal pump blade is mainly in the root and junction of the wheel cover, and the import value of stress concentration is larger than the outlet; the stress concentration may be caused easily as the stress increases rapidly in the blade, which has a great impact on the fatigue strength, the fatigue limit of the blade with the stress concentration is decreased more obviously than the fatigue limit of the smooth blade.

Abstract: The centrifugal pump is the common mechanical equipment, which is extensively applied in the water conservancy, ships and other projects. In this paper, the centrifugal pump body structure was analyzed based on the actual working conditions, and the structure was also optimized. The research results show that the maximum equivalent stress of pump body structure is in the tongue, when the grid cell size is 6mm, the maximum equivalent stress is 36.843MPa; The maximum equivalent stress increases as the grid cell size decreases, and the unit number increases rapidly as the grid cell size decreases; When the wall thickness of pump is selected appropriately, the material can be saved about 6%, and the optimized structure of pump can be also meet the structural performance requirements.

Abstract: The vibration noise control is critical in engineering fields and the phononic crystal provides a new mean to control the vibration noise. The band gap structure of one dimensional phononic crystal is studied in this paper. By using the equivalent masses method we obtain the band gap structure which depends on M, m and β, the influences of initial frequency of vibration band gap via the material density, the diameter of rod and the lattice constant are analyzed. The results show that the low-frequency broadband gap characteristic is obtained by increasing M and reducing m, β. The initial frequency of vibration band gap decreases as the metal material density, the diameter of metal rod or the lattice constant increase. Some conclusions from numerical calculation are examined by the vibration experiment.

Abstract: The liquid-conveying elbow is an very important part in the piping system, in this paper, the internal flow field in the pipeline elbow is studied, its structure is optimized, and the guide characteristic is improved. The results show that the internal total pressure difference in the original elbow is 29506.27 Pa, the Max-velocity is 7.12 m/s, and the internal flow field is very uneven；The internal total pressure difference can be greatly reduced through setting up the guide plates appropriately, its internal total pressure difference decreases as the number of guide plates increases, the Max-velocity decreases first and then increases as the number increases; When the number is a constant, the optimal result of guide plate according to the gold ratio arrangement is superior to the equidistance ratio arrangement; When the export length of guide plate is 50 mm, the total pressure difference is 14942 Pa in the elbow, comparing it to the result of the original elbow, it decreases 49.26%, the optimal design has an very obvious effect.

Abstract: The suspensory wire is widely applied in the fields of DVD CD-ROM head and various sensors. In this paper, the suspensory wires are analyzed with the SEM, X-ray energy spectrum and Hydrogen power spectrum et al. The research results show that the alloy composition of the suspensory wire is the composite materials, which is composed of silver, beryllium and copper bimetal; The Nano-indentation hardness tester is also did using the hanging Nano-indentation experiments on the suspensory wire, it’s to obtain more accurate mechanical properties parameters of material hardness and so on, then we get the average hardness of suspensory wire is 3.891 GPa; The average elasticity modulus decreases as the aging treatment time increases, and the average tensile strength increases as the aging treatment time increases.

Abstract: In the crystal growth process, the temperature distribution and concentration distribution at the solid-liquid interface edge are always the hot problems. In this paper, we study the concentration distribution at the solid-liquid interface edge under the natural convection conditions, we find that the concentration field is oscillating exponential decline or rose along the crystal growth direction. We also study the dendrite morphology of Al-La alloys using the experimental method, the results show that the microstructure of Al-35%La alloys is different from the common microstructure of hypereutectic alloy during the conventional casting process, the first crystalline phase is Al11La3, which composition is discontinuous along the growth direction, the main dendrite is composed of α-Al alternating with Al11La3, the results of SEM and XRD show that the chemical composition along the main dendrite exhibits periodic behavior, therefore, this microstructure is named as periodic diphase dendrite structure.