Vibration and acoustic data for a punch press

Mode shape, radiation ratio and damping data obtained from pure tone vibration shaker tests on a 170 kN mechanical C frame punch press are presented in this paper. The experimental results show the value of the radiation ratio to be very dependent upon the structure for frequencies below 1 kHz. Above this frequency the assumption of unity for the radiation ratio can be made. Values of the damping ratio are of the order of 0·01 for the modes which have been defined; however, data from blanking operations show that this value can increase by a factor of two to three.