A Three-Dimensional Model for the Surface Texture in Surface Grinding, Part 2: Grinding Wheel Surface Texture Model
In order to produce ground parts that have desirable surface properties, it is necessary to understand the evolution of these characteristics through the surface generation mechanisms involved in the grinding process. Since the geometry of the wheel surface, in part, determines the final workpiece geometry, the influence of the 3-D structure of a wheel surface on the final workpiece geometry is studied. In this work, a wheel surface model is developed that can be integrated with a surface grinding process model for simulating workpiece surface texture. The simulations utilizing the integrated model are used to study the workpiece surface roughness as a function of the frequency characteristics of the wheel surface. The 2-D Fourier forward and inverse transforms are employed to study and model the 3-D surface structure. In particular, the effect of specific frequency components in the wheel surface on the ground surface are analyzed. It is shown that workpiece surfaces resulting from wheel surfaces with dominant low frequency components have higher roughness, and that the low frequency components indicate a clustering of abrasive grains on the wheel surface. @DOI: 10.1115/1.1391428#
Modeling and Simulation of the Single Grain Grinding Process of the Nano-Particle Jet Flow of Minimal Quantity Lubrication
Along with strengthening of people's environmental protection awareness, the MQL technology has been used in grinding, but its limited cooling effect cannot satisfy the requirement of heat transfer enhancement in the grinding area. The new technology of nano-particle jet flow of MQL can effectively solve the heat transfer in the grinding zone and enhance the lubrication characteristics as well. This paper studies mainly the grinding process of the single grain under the condition of the nano-particle jet flow of MQL by establishing the kinematics model, elastic deformation model and plastic accumulation model of the single grain and simulating the value of the surface topography of the single-grain grinding workpiece with quenching 45# as the research subject. The results show that the grinding depth will exert a certain influence over the material deformation on the surface of the workpiece, the pile height and the length of the grinding crack. The yielding amount of the grain center δc and the elastic recovery amount of the materials on the surface of the workpiece δw increases with the grinding depth. The height of the material accumulation increases with the grinding depth. Furthermore, the change amplitude is large and the change gradient decreases correspondingly. The length of the grinding crack increases with the grinding depth, and the grinding depth and the height of the material accumulation have an approximate linear relationship.
Project management education: The human skills imperative
Abstract This paper is intended to provide an insight into the importance of human skills in project management success and the apparent lack of emphasis placed on this within the context of university education. The discussion will call upon the viewpoints of many notable authors in respect to the human or ‘soft’ skills that are necessary in the management of projects. Against this background a review will be conducted into how well project management literature and university education equips potential project managers in the area of human skills. As the PMBOK ® Guide is one of the major recommended texts in Australian universities offering project management education, the paper will identify that it predominantly emphasises the required ‘hard (technical) skills’ at the expense of the ‘soft (human) skills’. Subsequent discussion will highlight the need for a balance between hard and soft skills within project management education in universities. It will conclude that educators within this discipline should recognise the importance of incorporating greater human skills aspects into their educational programs.