High-Strain Rate Interlaminar Shear Testing of Fibre-Reinforced Composites Using an Image-Based Inertial Impact Test

Abstract

In this work a novel image-based inertial impact test is proposed to measure the interlaminar shear modulus of fibre-reinforced polymer composite materials at high strain rates. The principle is to combine ultra-high-speed imaging and full-field measurements to capture the dynamic kinematic fields, exploiting the inertial effects generated under high strain rate loading. The kinematic fields are processed using the virtual fields method to reconstruct stress averages from maps of acceleration. In this way, the specimen acts like a dynamic load cell, with no gripping or external force measurement required. This paper focusses on validation of the test principle using explicit dynamic simulations in ABAQUS. Simulations demonstrate the potential for the proposed method to identify the shear modulus at strain rates where current test methods become unreliable (500 s⁻¹ on average, and on the order of 2000 s⁻¹ locally). Access to spatial maps of stress averages provides opportunity to estimate the shear strength in the future. Further design work is required to amplify shear stress and strain in the specimen, after which the test will be validated experimentally. Eventually, the objective is to tailor the test to begin populating regions of a tension-shear failure envelope.