Load spectra of CNC machine tools

Load spectra of CNC machine tools are described in this paper; 112 CNC machine tools have been traced for 3 years. Data including machining parameters and conditions, drawings and NC programs of parts, process cards and specifications of each individual CNC machine tool are gathered. A database containing this information is designed. The loads of CNC machine tools are calculated and the distribution parameters of loads are estimated. A fuzzy multicriteria comprehensive evaluation method is applied to evaluate the fitness of the distribution model. This methodology lays a foundation for the reliability designs of CNC machine tools. Copyright © 2000 John Wiley & Sons, Ltd.