Abstract
This paper describes the investigation of thermoelastic effect and damage process in carbon fiber reinforced thermoplastic composite laminates through thermoelastic stress analysis. Symmetrically orthotropic model laminate specimens having 4-layers of carbon fibers using spread tows and Nylon-6 were conducted to tension-tension fatigue tests. In order to estimate the thermal conduction effects due to thermoelastic effects generated in the sub-layer in a specimen under fatigue test, the measurement employed all of delayed phase emission via FFT processing the data recorded by Lock-in therrnograpy. Evidently, the processed thennoelastic images (TSA images) brought the information from the second or third layers. Thermoelastic damage analysis (TDA) between two TSA images, proposed by one of the authors, detected splitting and/or transverse matrix cracks in the notched root of a specimen and TDA information also showed a possible quantitative estimation of damage development.
