Constrained damping and free damping sound insulation structures were prepared by bonding galvanized steel sheet and damping rubber with Kemlock adhesive and pressing through high temperature mold of flat vulcanizing machine. It is shown that both the constrained damping structure and the free damping structure can improve the sound insulation performance of the single-layer plate and restrain the resonance region and the coincidence effect region

and the constrained damping structure is better than the free damping structure. The sound insulation performance of the restrained damping structure is improved slightly with the increase of layer number of the sound insulation plate

and the rubber damping layer with 1 mm in thickness can effectively restrain the resonance and coincidence effect. Vibration simulation of damping layer of the constrained damping structure shows that noise causes vibration deformation of the damping layer

and deformation of the damping material transforms vibration energy into heat energy so as to suppress resonance and improve its sound insulation performance.