Characteristic analysis of journal bearing under thin film lubrication—Layered Viscosity Model
Journal bearing is a kind of widely used bearing and its study never stops. The analysis is carried to journal bearing with layered viscosity model in this paper. Layered Viscosity Model regards viscosity as piecewise function and averages every segment in order to get more accurate expression, and the pressure distributing, load capacity and friction are obtained for journal sliding bearing under thin film lubrication. The condition of thin film lubrication actualizing is made certain. The theoretical base is provided for the analysis of aggradation and liniment surface layer lubrication. This work could promote the understanding and research of the mechanism of the nano - scale thin film lubrication.
Velocity Analysis for Continuous Viscosity Modelunder Thin Film Lubrication
The lubrication of bearings is directly affected by the flow properties of the liquid lubricant. One key feature of lubricant is its viscosity distribution in the bearing. The distribution is dependent on the adsorbent properties of the surface and the velocity distribution of the lubricant. This paper is only connected with the velocity analysis on the cross-gap flow. Because of increasing the speed, apart from increasing the temperature, the other features of lubricant will be changed. This paper describes the fluid velocity profiles for continuous viscosity model in the bearing.
Evaluation of buckling load and dynamic performance of steel shear wall retrofitted with strips made of shape memory alloy
One of the most imperfections of the steel shear wall is out of plane displacements that cause severe damage in both structural and non-structural elements. In this paper, the effects of shape-memory alloys on steel shear walls are investigated. First, a numerical analysis using the finite element method in ABAQUS software has been carried out according to an experimental test. The results of the numerical analysis have been verified with experimental results. Next, shape-memory alloy fibers have been added vertically and horizontally to various parts of the steel shear wall. The results show that retrofitting with the shape-memory alloy reduces the out-of-plane displacement of the steel shear wall under both cyclic and seismic loadings. Besides, the buckling load in the steel shear wall increases when it is retrofitted with the shape-memory alloy. Also, the total out-of-plane movement (accumulated absolute displacements) of the steel shear wall and non-structural damage are controlled by the characteristic of a shape-memory alloy material called “super-elastic”.