Development and Validation of a Finite Element Model for Flax/Epoxy–Epoxy Honeycomb Sandwich Panels Toward Self‐Healing Applications

ABSTRACT The growing demand for lightweight, sustainable, and repairable structures has led to increased interest in natural fiber–based sandwich composites. This study presents the development and validation of a finite element (FE) model for flax/epoxy–epoxy honeycomb sandwich panels, focusing on their mechanical performance and failure behavior under tensile and flexural loading. The panels were fabricated using the vacuum‐assisted resin transfer molding (VARTM) process, incorporating flax/epoxy composite face sheets and an epoxy honeycomb core. Comprehensive mechanical characterization of the constituent materials was performed, followed by three‐point bending tests to evaluate the flexural response and failure mechanisms of the sandwich structure. A physics‐based digital twin framework was established using ANSYS Workbench with the LS‐DYNA explicit solver, enabling accurate simulation of progressive damage evolution and close reproduction of the experimental load–displacement behavior. The numerical predictions showed strong agreement with experimental observations, successfully capturing the key failure modes such as core crushing, face‐sheet rupture, and interfacial debonding. The validated FE model provides a robust computational foundation for optimizing the structural design of natural fiber sandwich composites. Beyond conventional mechanical evaluation, this modeling framework establishes a scalable platform for future integration of self‐healing mechanisms, offering predictive insight into the durability and recovery performance of sustainable composite systems.