Modal control of planar oscillation of slotted sonotrodes for ultrasonic welding of plastics

With account of geometry conditions two-dimensional problem statement of planar oscillations of variable thickness plates under cyclic loading is derived from simplified model of mechanical behavior of dissipative bodies under high frequency excitation. Model developed is applied for simulation of vibration of sonotrodes for ultrasonic welding of plastics and metals. The problem is to obtain uniform distribution of normal displacement on operated face of a rectangular plate by means of a number of slots, lateral grooves and adjoining of correcting rods have been studied. Each such method efficiency has been estimated. It is shown that their simultaneous utilization permits to obtain the degree of homogeneity sufficient for practical applications even for the plates whose length exceeds the doubled length of longitudinal wave.