In order to meet the actual demand of noise reduction of internal combustion engine,the three-dimensional dynamic model of piston assembly was established based on the Ricardo-Pisdyn software taking into account the surface roughness,thermal and elastic deformation of piston and cylinder liner. The influence of structure parameters,such as cylinder clearance,piston-pin offset and skirt profile,on the piston striking energy is systematically studied. The results showed that the cylinder clearance gap has a s...