# The Fracture Mechanism of Impact-Resistant Bionic 3D Model Structures Inspired by Composite Structure of Mantis Shrimp Appendage

## TL;DR

This paper studies how the structure of mantis shrimp appendages can inspire impact-resistant composite materials with improved energy absorption.

## Contribution

A novel bionic composite structure with rigid outer and flexible inner layers is proposed, inspired by mantis shrimp anatomy.

## Key findings

- Bionic fiber arrangements in X-Y and Y-Z planes improved kinetic energy absorption by 94% and 109%, respectively.
- The design reduced catastrophic damage in the impact center by optimizing crack propagation.
- Interlayer connections and crack distribution optimization enhance energy dissipation in composites.

## Abstract

To improve the impact resistance of composite materials, this study adopted the structures in the impact region of mantis shrimp appendages as a bionic prototype, designing a composite structure with a rigid outer layer and flexible sinusoidal inner layer. Meanwhile, bionic arrangement was conducted on the fibers in three directions (X-Y, X-Z, and Y-Z planes) within the flexible layer to regulate the crack propagation path during the impact process. Finite Element Method and low-velocity impact tests were carried out to verify the structural effectiveness, analyze the energy absorption mechanism, and investigate the failure modes. Relative to the basic rigid-flexible structure, the brick-and-mortar (Y-Z) and vertical-horizontal alternating fiber (X-Y) models show a 94% and 109% improvement in kinetic energy absorption efficiency, respectively. Additionally, the catastrophic damage in the impact center area caused by crack concentration is significantly reduced. This study confirms that the bionic 3D arrangement of fibers can realize interlayer connection, optimize crack distribution, and enhance energy dissipation, thereby improving the impact resistance of composite materials.