Abstract: The mechanical properties of formed components are significantly influenced by the prevailing residual stress state. Single point incremental sheet metal forming is a flexible manufacturing process for complex shaped parts that enables to adjust the residual stress state by a variation of the process parameters. In this paper, truncated cone geometries with increasing relative tool step-down increments are cyclically loaded to analyze the influence of the process parameters on the fatigue strength of the formed components. The fatigue strength decreases due to resulting tensile residual stresses on the tool-side of the cone with decreasing relative tool stepdown increments. The maximum reduction of the fatigue strength caused by residual stresses is 42% in the investigated range of the relative tool step-down increments. The tensile residual stress amplitudes on the tool-side increase with an increasing number of step-down increments for the same final geometry.
Authors: F. Maaß, M. Dobecki, M. Hahn, W. Reimers, and A.E. Tekkaya
Keywords: Single Point Incremental Forming, Residual Stress State, Fatigue Strength