Optimal Load Sharing in Bioinspired Fibrillar Adhesives: Asymptotic Solution

Abstract

We propose here an asymptotic solution defining the optimal compliance distribution for a fibrillar adhesive to obtain maximum theoretical strength. This condition corresponds to that of equal load sharing (ELS) among fibrils, i.e., all the fibrils are carrying the same load at detachment; hence, they all detach simultaneously. We model the array of fibrils as a continuum of linear elastic material that cannot laterally transmit load (analogous to a Winkler soil). Ultimately, we obtain the continuum distribution of fibril's compliance in the closed-form solution and compare it with previously obtained data for a discrete model for fibrillar adhesives. The results show improving accuracy for an incremental number of fibrils and smaller center-to-center spacing. Surprisingly, the approximation introduced by the asymptotic model shows reduced sensitivity of the adhesive strength with respect to misalignment and improved adhesive strength for large misalignment angles.