Shot peening in shape deposition manufacturing

Abstract: "Experimental results and their analysis are presented concerning the use of shot peening as a means of altering the geometries of residually stressed metals. The application of this research is to parts that are built up by the successive deposition of metal layers using shape deposition manufacturing. The goal of this work is to obtain qualitative and quantitative results which can be integrated into the design and planning of shape deposited parts. The results of shot peening experiments conducted on steel specimens are presented along with a model of shot peening. This model enables the calculation of the stresses, strains, and curvatures induced by shot peening, based on the measured strains, as a function of the amount of peening. Using this model, two types of analyses of the peening tests have been conducted including an analytical beam- based analysis and a numerical finite element analysis. Quantitative and qualitative results are presented concerning the effectiveness of shot peening in producing shape changes in a manufactured part. One of the primary conclusions drawn from these experiments is that the peening efficiency is a function of the thickness of the specimen, due to the manner in which compressive stresses develop in the shot peened portion of the part."