Multi-blade monolithic Euler springs with optimised stress distribution

Euler springs are used for vertical suspension and vibration isolation as they provide a large static supporting force with low spring-rate and use minimal spring material. To date multiple single-width rectangular blades of uniform thickness and stacked flat-face to flat-face, have been used in the post buckled state, with half of the number buckling in each of opposing directions. This structure requires clamping the ends of the blades giving stick-slip problems. In this study we investigate the benefits of forming side-by-side oppositely buckling blades from a single monolithic sheet of spring material. We investigate how to distribute the stress evenly along the length of the blade by contouring its width, as well as finding the optimal joining contour to distribute the stress evenly around the tearing joints between oppositely bending blade sections. We show that this optimal shaping typically improves the spring working range by over 60% compared to an equivalent rectangular blade.