Crack Detection in Metallic Plate Elements Using a Point-Based Thermal Measurement Strategy

Abstract

This paper presents a method of thermography-based damage detection that employs an economic sensor setup that is feasible for permanent deployment in operational structures. The setup includes a joule (resistive) heating element and an array of IC temperature sensors mounted to the boundary of a metallic plate. As the heat is conducted from the resistor through the metal, sensors measure the time variance in temperature rise at the sensor locations. This data can then be used in an inverse manner using a high-fidelity finite element model (FEM) to solve for imperfections in the metal that cause delays in heat conduction. Aluminum plate specimens with and without damage are used. Sensor data is collected via wireless sensing nodes. Correlations between the finite element and the IC temperature sensor system data are analyzed.