Pseudo Rigid Body Model for Nonlinear Folding Contact-Aided Compliant Mechanism

Folding contact-aided compliant mechanisms have the potential for innovative designs tailored for specific applications such as energy absorption, shape morphing, or stress relief. This tailorability relies on multiple variables that define the geometric and material behavior. The combined effort of the geometric and material nonlinearity can emphasize certain features in the design that, individually, would not be possible. Folding as a concept is very important in origami engineering and requires careful choice in the design variables when it comes to dimensions and material properties. Using finite element analyses for folding at the level of a unit cell, as well as the overall structural design, has shown to be cumbersome and computationally expensive. Therefore, in this work, a segmented pseudo rigid body model that captures a high level of flexibility is developed for both a superelastic and hyperelastic material. By increasing the number of segments, the model allows the structure to undergo large deformations. The results from the segmented model are compared with FEA for the folding contact-aided compliant mechanism. 3D-printing and experimental testing of the folding mechanism is also explored