Rapid Fatigue Characterization via Infrared Thermography of AM-CM Composites

A direct correlation exists between the microstructure of a composite (defect distribution, residual stresses, fiber geometry, and orientation) and the global composite mechanical behavior. Manufacturing processes govern the composite microstructure characteristics; thus, rapid process–microstructure–performance relationships must be established for emergent materials and manufacturing processes. In this chapter, a preform was manufactured via a modified Additive Manufacturing followed by Compression Molding (AM-CM) process with carbon fiber (CF) filled acrylonitrile butadiene styrene (ABS). The AM-CM plates were prepared with varying process parameters yielding distinct composite microstructures with varying porosity and fiber orientations. Micro-computed tomography has been used to characterize the microstructure of these composites. Preliminary mechanical testing (static) was conducted to ascertain these composites’ static strength and stiffness properties. The current chapter strives to correlate the microstructure of these composites with their fatigue performance using rapid infrared thermography (IRT). A typical “staircase” loading has been adopted for IRT-based fatigue testing via self-heating. The stabilized temperature versus applied maximum stress profile plots yields a bi-linear curve indicating a pseudo-fatigue limit of each composite configuration. This bi-linear curve, coupled with stiffness degradation plots, can map composite microstructure with its fatigue performance. The approach outlined will provide a basis for rapidly characterizing and inserting emergent materials and manufacturing processes in fatigue-critical applications.