Infrared Thermography Parameter Optimization for Damage Detection of Concrete Structures Using Finite Element Simulations

In this research paper, defect identification is carried out on a concrete block specimen. A finite element modelling software is used to simulate a 3D model of Concrete Block Specimen with different thickness of air void defect embedded at different location. The Concrete Block Specimen is heated using lock-in infrared thermography concept in the models to identify the location and other details about the defects. In lock-in infrared thermography, the model is heated repeatedly at regular intervals for required frequency and responses of the heating on the model is noted. The excitation power of 200-Watt, 500-Watt, 1000-Watt and 2000-Watt were used with 12 different heating periods, which were set from 5 to 60 min with 5 min interval. The duty cycle for each heating period was taken as 50%. Different data like thermal images, temperature difference on the defects, graphs of temperature v/s surface were found. Using a MATLAB program, area of the defects were calculated based on thermal images. An effort is made to find exact amount of heating and time required for a concrete structure to identify defects using simulation of Infrared Thermography in FEM. The area of defects estimated at 60 min for 55 min time period was close to the actual area of defects with minimum error.