A Theoretical Model for Structural Health Monitoring of the Thermal-Mechanical Behaviour of Plates Under Combined Laser Irradiation and Airflow

Laser irradiation, as a high-energy input, induces a rapid temperature rise on a structure’s surface, resulting in a localized stress concentration, which is one of the key elements in catastrophic failure. Accurate structural health monitoring of plates should take stress distribution into account. In this paper, we present a theoretical model for determining the stress state of a plate under combined laser radiation and airflow, using temperature values from several discrete measurement points as input. First, a fitting function was proposed based on data-driven thermal analysis, which is utilized to acquire the temperature distribution on the whole surface. The stress state near the area of the laser radiation was then calculated using a theoretical model based on the elasticity theory of an axis-symmetric problem. With the incorporation of the data-driven method, the model is then extended from a baseline analytical model to account for three-dimensional heat-conduction effects and the nonlinear temperature dependence of thermophysical properties. The effectiveness and precision of the proposed model were verified by coupled thermal-mechanical simulations. The current work can provide substantial support for developing a structural health monitoring system for aerospace structures exposed to laser radiation.