UC Davis

Industrial energy consumption accounts for 35% of all energy consumed in the United States andenergy consumed by machine tools in manufacturing processes contributes a significant portion to the inefficiencies in manufacturing energy consumption. However, there are only few energy efficiency models for machine tools which also include product quality. Therefore, this research investigates the hypothesis that physics-based models of machine tools and processes lead to more energy-efficient machine tool design. Furthermore, the research will focus on abrasive machining, primarily using grinding machines and will highlight the quality aspects of finished workpieces. The research then addresses the following research tasks. 1) to analyze the energy efficiency of grinding machine tool components. This assessment included applying the axiomatic design methodology to identify those machine tool components, and then creating physics-based models of those components. Use of these models will allow designers to easily calculate energy consumption of a machine tool feed system. 2) To model grinding machine motors for energy consumption in the manufacturing and use phases. This work included performing a literature review of the life cycle inventory models of electric motors, and creating an embodied energy model using the review. This also included performing a study of the energy consumption of a grinding spindle, to identify start-up times for minimum energy consumption and minimum peak power. The two tasks highlighted can be used by machine designers to first determine the embodied energy of their design for energy tradeoff analyses, and second to reduce energy and peak power during the use phase. 3) To investigate the correlation between machine tool energy consumption and workpiece quality. This work included performing a study on energy consumption and resulting surface roughness of grinding steel using cold air for coolant. It was identified that a correlation does exist, that higher energy consumption is correlated with lower surface roughness.