Programmable assembly of bi-walled nonuniform beams: Concept, modeling and performance

Abstract

Postbuckling structural instabilities has been shown to have useful mechanical characteristics such as well deformation resistance and recovery. However, the difficulties in control and programmability, due to the complex interconnected sensitivities to geometric and material properties, severely hinder the phenomenon use in multifunctional structural applications. In this paper, we propose a concept of nonuniform beam assembly to increase the the controllability of the postbuckling response. Bilaterally constrained, nonuniform beams are theoretically investigated to obtain the buckling instability, and the predictions are compared with the experimental and numerical results with satisfactory agreements. Parametric studies are carried out to demonstrate the tunability of the reported beam assembly with respect to the geometric properties and material parameters (i.e., Young's modulus) of the nonuniform beams. Finally, the use of the proposed beam assembly method is investigated for novel applications as mechanical triggers and deformation detectors. This study demonstrates an exciting approach to tune the mechanical characteristics of engineered assembly structures for novel applications, such as material embedded mechanical sensing.