Multiscale Simulation Approach to Localized Interfacial Bonding and Stress -State Analysis of Self-Triggering Sensors

Abstract

Integration of structural sensors and health monitoring has been an interest of the composite research community for the past thirty years. Advances in the design, development, and applications of multifunctional materials is an important aspect of 3rd generation material structures. This work investigates utilizing self-triggering mechanoluminescent sensors integrated in composite structures for applications such as fiber-reinforced repair. The mechanism for luminescent excitation is dependent on the stress transfer of the localized interface as a result of the global damage event. Single lap-shear tests were simulated using a three-scale finite element (FE) model to provide insight into the localized and global deformations. This model accurately captured the global lap-shear test in addition to the fiber optic sensor and the local scale sensor coating, including TL particles. Crack propagation was contained within the analysis to include interfacial influence on accumulating damage. Shear deformation of the fiber optic sensor and the resulting stress transfer to the mechanoluminescent particles is successfully aligned with the structural health monitoring mechanism. This investigation is the intersection of numerous digital manufacturing modes, containing co-manufactured structures between robotic agents, in-situ hybrid additive design towards composites, and digital twin formulation to propel smart manufacturing infomatics. High-fidelity digitization of a physical model augments finite element inspection to a degree never before published, as the stress-state condition of the adhesive and selftriggering particles, probed at a local level, have results compared across all three scales simultaneously. The mechanical responses obtained prove to be far more insightful to the physical system at the nanoscale, in comparison to conventional simulations.