Toward the automated determination of structural detail geometry for a target fatigue life

A method for valuation of allowable stress concentration factors (SCFs) and hence the local geometry of structural details subject to complex loading is developed to meet a specified target fatigue life. The method is based on the local strain approach to fatigue, and takes into account the long term loading history. On the condition that cumulative fatigue damage equals unity, an upper bound of the allowable SCFs conditional on a selected mode of loading is found, and the corresponding changes to the initial detail geometry are determined. In the general case of multiple loading modes, the procedure normally needs to be repeated, until overall convergence in geometry occurs. The method is supported by necessary software and an SCF database.