Characterization of Wrinkles and Periodic Variations in Material Using Infrared Thermography

摘要

Methods for identifying and quantifying wrinkles in a composite structure by processing infrared image data. The intensity and first and second time derivatives thereof at a particular time can be displayed as thermography line profiles on a graph in which the horizontal axis represents the pixel number across the field of view of an infrared camera. The spatial derivatives of the foregoing thermography line profiles can also be calculated and displayed as a graph. The maximum amplitude (i.e., height) of an out-of-plane wrinkle can be determined using a correlation/calibration curve that is constructed by correlating infrared image data with optical measurement data. In addition, the wavelength and maximum amplitude of an in-plane wrinkle can be measured directly from the thermography line profiles.