INVESTIGATE THE INFLUENCES OF SHOT PEENING ON THE FATIGUE LIFE OF VIBRATING CYLINDER BLOCK FOR A NEW FREE PISTON LINEAR ENGINE

Recently, applications of Aluminum (Al) use have extended into the area of the lightening of engine parts. However, the hardness of Al is lower than that of the steel mainly used for those engine parts at present. Therefore, it is necessary to carry out surface modifications of Al in order to use it in moving parts. Shot peening is widely used as a processing tool to increase the fatigue and wear resistance of engine of carbon or alloy steels, etc. This paper presents investigate the influences of shot peening on the fatigue life improvement of aluminum alloys vibrating cylinder block of a new two-stroke free piston engine. The finite element modeling and frequency response analysis are employed in this paper. The finite element modeling and frequency response analysis have been performed using finite element analysis codes and the fatigue life prediction was carried out using finite element fatigue analysis commercial code. Based on the finite element results,different frequency response approaches were applied to predict the fatigue life of free piston linear engine cylinder block. It is observed that the Dirlik method gives the bestcomparable results pseudo-static time domain approach with the frequency response techniques. Results indicate the great influences for shot peening and all surface finish processes. It is concluded that forged surface finish conditions found the highest life after the shot peening process. . Therefore, the shot peening process is the promising surface treatments for aluminum alloy parts to increase the fatigue life of the free piston linear engine cylinder block