Modelling of Metastable Equilibrium State using PRB Principles

Master thesis (2019)

Authors

K.D. Kommuri Mechanical Engineering

Contributors

J.L. Herder Precision and Microsystems Engineering (mentor)
F.G.J. Broeren Mechatronic Systems Design - Mechanical, Maritime and Materials Engineering (mentor)
G. Smit Medical Instruments & Bio-Inspired Technology - Mechanical, Maritime and Materials Engineering (graduation committee member)
Milton Aguirre (graduation committee member)
Faculty
Mechanical Engineering, Mechanical Engineering
Copyright: © 2019 Krishna Dheeraj Kommuri
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Published Date

25-11-2019

Language

English

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Faculty

Mechanical Engineering

Abstract

This thesis proposes the introduction of a metastable equilibrium state in a viscoelastic pre-curved beam. Generally, metamaterials with bistable unit cells need an external application of force to restore, leading to the contemplation of possible structures with self restorable behaviour. Such restorable nature is associated with metastable equilibrium, which is a time-dependent equilibrium state. The objective of the topic is to build a proof of concept for metastability in a pre-curved beam and identify the influence of geometric parameters on metastability. In the course of the thesis, various models of bistable designs are classified. A feasible bistable mechanism was selected, and the metastable nature is introduced through viscoelasticity. In this thesis, an analytical model is formulated by combining an equivalent Pseudo Rigid Body (PRB) model of the pre-curved beam (modelling the beam's compliance) with Standard Linear Solid (SLS) model (modelling the beam’s viscoelasticity). Prototypes are manufactured by using FDM printing of TPU material. Experimental studies are performed for the evaluation of material properties and testing for metastability in pre-curved beams with various shape factors. The results of experimental studies proved the possibility of metastable equilibrium in viscoelastic pre-curved beams. Later, discussions are offered to improve the predictability of metastability in pre-curved beams and the scope for future studies.