Regulation of notch sensitivity of lattice materials by strut topology

TL;DR

This paper introduces a local reinforcement method for lattice materials near stress concentrators, optimizing strut waviness to enhance strength and ductility through finite element analysis.

Contribution

It presents a novel approach to reinforce lattice structures locally by adjusting strut waviness, improving mechanical properties near stress-raisers.

Findings

Optimized waviness distributions increase tensile strength.

Different lattice geometries respond uniquely to waviness modifications.

Finite element analysis effectively predicts macroscopic responses.

Abstract

We propose a local reinforcement technique for lattices in the vicinity of a stress-raiser such as a notch, in order to elevate the macroscopic strength and ductility. A spatially non-uniform waviness distribution of sinusoidally-shaped struts is assumed in the vicinity of the notch, and the sensitivity of macroscopic tensile response to strut waviness distribution is studied by finite element analysis. Optimized lattice structures are determined in order to maximise the macroscopic tensile strength or ductility from these various strut waviness distributions. Both hexagonal and triangular lattices are studied as these geometries are representative of bending-dominated and stretching-dominated lattices, respectively.