Quadrupole simulations of passive thermography in composites

Passive thermography has been shown to be an effective method for in situ and real time nondestructive evaluation (NDE) to measure damage growth in a composite structure during cyclic loading. The heat generation by subsurface flaws results in a measurable thermal profile at the surface. To better understand these sources, the quadrupole method is used to simulate the resultant temperature profile for a subsurface heat source. The simulations are compared to finite difference and finite element simulations of the same sources and experimental data acquired during cyclic loading of a composite specimen.