Nipping analysis of a two-leaf spring strengthened by an additional full-length leaf

Nipping analysis of a rectangular two-leaf spring strengthened by an additional full-length leaf is presented. Closed form expressions are derived for the initial gaps between the leaves which make the maximum stresses in all the leaves within the clamped cross-section of the loaded spring equal to each other. The derived expressions are general in the sense that they apply for any values of the introduced leaf-length and thickness parameters. Two initial gaps between the pairs of consecutive leaves are needed to achieve the desired stress reduction. The required gaps can be either positive or negative, depending on the values of introduced spring parameters. For some combination of length and thickness parameters, nipping is not an effective means of stress reduction. There is a particular combination of parameters for which the maximum stresses in all critical cross-sections of leaves become equal to each other. The presented analysis and obtained results may be useful for multi-leaf spring design and related optimization studies.