Through theoretical derivation and finite element simulation

the difference between the actual node position and the theoretical node position of the stepped horn is found.At the same time

the lateral deformation of material will occur when the ultrasonic wave transmit in the stepped horn is presented.That is to say

the longitudinal elastic deformation will induce to generate the lateral deformation of material because Poisson ratio exist.The vibration character of the stepped horn is analyzed.That the node disk can be reduced by moving the node position to the thin side is pointed out.Through the experiment about the node position of the horn

the results show that above-mentioned conclusion is correct.