Shape of Anodizing Rack Clips

We do bright dipping and anodising of aluminium parts for the automotive sector. I am not happy with the titanium clips on the jigs.....they crack or lose their 'springiness'. One approach is to alter the profile of the clips from the present "Square-U" to a more hourglass shape. My thinking is that the clip/unclip cycle stresses will be spread along the curved profile rather than concentrated in the small radius at each bend. Ideally I would like to keep stresses within the elastic limit or at least extend the cycle life of the clips.

I need equations that demonstrate the relationship between stress & radius of curvature (hopefully well below the plastic limit)or something similarly useful. With such data in hand, I can calculate compromises with process / cost constraints etc to achieve the 'optimal' (!) design. Is there anyone out there who can help?