Optimal design of composite granular protectors

TL;DR

This paper uses an evolutionary algorithm to optimize the design of one-dimensional granular chains for protective purposes, focusing on minimizing transmitted force through topology, size, and material adjustments.

Contribution

It introduces an optimization framework for granular protectors that results in novel, high-energy equipartitioned waveforms and pulse transformations for improved protection.

Findings

Optimized protectors produce extended, low-amplitude pulses.

High-energy equipartition occurs in the optimized chains.

Transformations of incident waves into solitary pulses enhance protection.

Abstract

We employ an evolutionary algorithm to investigate the optimal design of composite protectors using one-dimensional granular chains composed of beads of various sizes, masses, and stiffnesses. We define a fitness function using the maximum force transmitted from the protector to a "wall" that represents the body to be protected and accordingly optimize the {topology} (arrangement), {size}, and {material} of the chain. We obtain optimally randomized granular protectors characterized by high-energy equipartition and the transformation of incident waves into interacting solitary pulses. We consistently observe that the pulses traveling to the wall combine to form an extended (long-wavelength), small-amplitude pulse.