Applying Ultrasonic Thermotomography and Electric-Loading Thermography for Thermal Characterization of Small-Sized Defects in Complex-Shaped Spatial Composite Structures

A complex technique for thermal characterization of small-sized defects such as discontinuities in intricately shaped composite structures is presented. The complex defect characterization technique is based on revealing and identifying internal defects as sources of heat due to extraneous stimulation sources. The use of this complex technique makes it possible to identify types of defects that remain virtually unnoticed with the existing methods, for example, defects of small sizes, closed cracks, microcracks, etc. and determine their location in the material. It is shown that the error in determining the depth of defects in the material by the proposed integrated technique is better than 10–15%, a figure that is quite acceptable for practical usage.