Abstract
In the manual impact excitation technique, which is usually used for the measurement of structural dynamic stiffness of machine tools and other machineries, it is necessary to repeat impact excitations and average the measured data to remove the effect of disturbances. However, it is difficult to repeat the same excitations exactly because of the manual operation. Consequently, too weak impacts or multiple impacts, which result in poor signal-to-noise ratio, often occur. The present paper describes a practical measuring method in which a reference exciting force and certain permissible deviations are determined in advance and only the excitations within the permissible range are accepted. Experimental results show that the proposed method is not only useful to the improvement of measuring accuracies but also helpful to the investigation of nonlinear characteristics of the structures.
