# Repeated Impact Damage Behavior and Damage Tolerance of Bio-Inspired Helical-Structured Glass Fiber Resin Matrix Composites

## TL;DR

This paper studies how bio-inspired helical structures in composite materials improve their ability to withstand repeated impacts and resist damage.

## Contribution

The novel contribution is the design and analysis of cross-helical and symmetric-helical composite structures for enhanced impact resistance.

## Key findings

- Cross-helical and symmetric-helical structures showed improved resistance to multiple impacts.
- Ultrasonic C-scan and X-ray CT revealed interlaminar damage propagation mechanisms.
- Three optimized bionic configurations were developed based on finite element modeling.

## Abstract

This study proposes a bionic helical configuration design concept, focusing on glass-fiber-reinforced polymer matrix composites. Through a combination of experimental and numerical simulation methods, it systematically investigates the resistance to multiple impacts and damage tolerance. The research designs and fabricates two types of bionic laminates: a cross-helical and a symmetric-helical structures. By conducting repeated impact experiments at 5 J of energy for 1, 5, 10, and 15 impact times and employing advanced characterization techniques, such as ultrasonic C-scan and X-ray CT, the study reveals the mechanisms of interlaminar damage propagation and failure characteristics. Based on experimental findings, a finite element model encompassing the entire impact process and post-impact compression behavior is established. Utilizing this model, three optimized novel bionic configurations are further developed, providing new insights and theoretical support for the structural design of high-performance impact-resistant polymer matrix composites.