Master's Thesis Proposal

Victor Riera Naranjo

(Advisor: Prof. Bolei Deng)

Crack Propagation in Soft Lattice Metamaterials: Effects of Strand Non-Linearity and Analogy with Neo-Hookean Materials
On
 

Monday, March 24 

3:00 p.m. 
Weber Building 200 Conference Room
 

Abstract
Soft lattice metamaterials (MMs) exhibit highly non-linear properties, as described by hyperelastic theory, which leads to unconventional fracture behavior. Traditional linear elastic fracture mechanics (LEFM) assumptions do not hold in this regime, resulting in unexpected crack propagation dynamics. Notably, critical stress and crack propagation speeds deviate significantly from classical predictions, with some cases exhibiting supersonic fracture that appears to challenge thermodynamic constraints.
This thesis focuses on the computational study of crack propagation in lattice MMs composed of hyperelastic strands, aiming to parametrize crack propagation speed based on network and strand properties. To achieve this, we formulated a mathematical model for the individual strand behavior and developed an ad hoc dynamic fracture simulation using MATLAB. Preliminary results indicate a strong correlation between material non-linearity and crack propagation speed, though further validation is necessary to refine control variables across different non-linearity levels.
From these findings, we aim to establish a scaling law for crack propagation speed, provide a qualitative explanation for the observed behavior, and draw an analogy between neo-Hookean materials and soft lattice MMs. These insights could enhance our understanding of fracture dynamics governing soft lattice MMs and the propagation of crack waves through their bulk.
 

Committee
•    Prof. Bolei Deng – School of Aerospace Engineering (Advisor)
•    Prof. George Kardomateas – School of Aerospace Engineering
•    Prof. Christos E Athanasiou – School of Aerospace Engineering