Active Infrared Thermography for Interfacial Defects Detection on Composite Cross-Arms Based on Finite Element Simulation

Composite transmission towers have become a key trend in the development of transmission and substation systems in recent years, and composite cross-arms have begun to replace traditional steel cross-arms in some lines. The interface of composite cross-arms, on the other hand, might be faulty owing to its variables and external environmental influence. Existing detection technologies have several limitations, and active infrared thermography, as a new technology, has demonstrated its efficacy in identifying faults in composite materials. In this work, the thermal response characteristics of composite cross-stretcher interface flaws are comprehensively investigated using the finite element simulation method. The thermal response characteristics of interface defects of various sizes, depths, and kinds are compared, and the temperature variation characteristics of the defects are described using linear and logarithmic coordinates. The nature of the defect can be extracted from the rate of temperature change and the temperature in the smooth phase in linear coordinates, and the nature of the defect can be extracted from the curve shift time, magnitude, and direction in logarithmic coordinates. The research presented in this work demonstrates that active infrared thermography can effectively distinguish interface defects in composite cross-arms.