Towards Pseudo-Rigid Body Models for Mechanical Metamaterials: Analysis and Design of Tubular Structures

Pseudo-rigid body (PRB) modeling is a well-known technique from the field of compliant mechanisms. This technique approximates the behavior of compliant mechanisms, which rely on bending elements instead of hinges for their motion, by a classical rigid body mechanism where springs add stiffness to the hinges. This allows us to describe and design compliant mechanisms without having to use elaborate and computationally expensive continuum elastic models.

Here, I will present how PRB models can also be used for the analysis and design of mechanical metamaterials. Many mechanical metamaterials obtain their unusual properties from a bending-dominated internal mechanism, which can be accurately described by PRB models. This approach makes it possible to describe and predict the kinematic and elastic properties of these materials analytically, leading to a more efficient and rational design methodology.

I will demonstrate this technique by the example of a tubular mechanical metamaterial. I will show that the PRB model matches the experimentally determined behavior and show how this model can be used to modify the structure to include new mechanical properties.