title: Optical sensing of the fatigue damage state of CFRP under realistic aeronautical load sequences.
abstract: We present an optical sensing methodology to estimate the fatigue damage state of structures made of carbon fiber reinforced polymer (CFRP), by measuring variations on the surface roughness. Variable amplitude loads (VAL), which represent realistic loads during aeronautical missions of fighter aircraft (FALSTAFF) have been applied to coupons until failure. Stiffness degradation and surface roughness variations have been measured during the life of the coupons obtaining a Pearson correlation of 0.75 between both variables. The data were compared with a previous study for Constant Amplitude Load (CAL) obtaining similar results. Conclusions suggest that the surface roughness measured in strategic zones is a useful technique for structural health monitoring of CFRP structures, and that it is independent of the type of load applied. Surface roughness can be measured in the field by optical techniques such as speckle, confocal perfilometers and interferometry, among others.
authors.affiliation: Instituto Nacional de Técnica Aeroespacial (INTA), Carretera de Ajalvir Km 4, 28850 Torrejón de Ardoz, Spain. zuluagarp@inta.es.|Department of Applied Physics, ETSI Minas, Universidad Politécnica de Madrid, C/Ríos Rosas 21, 28003 Madrid, Spain. zuluagarp@inta.es.
authors.forename: Pablo
authors.initials: P
authors.lastname: Zuluaga-Ramírez
authors.affiliation: Department of Applied Physics, ETSI Minas, Universidad Politécnica de Madrid, C/Ríos Rosas 21, 28003 Madrid, Spain.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Arconada
authors.affiliation: Instituto Nacional de Técnica Aeroespacial (INTA), Carretera de Ajalvir Km 4, 28850 Torrejón de Ardoz, Spain. frovelm@inta.es.
authors.forename: Malte
authors.initials: M
authors.lastname: Frövel
authors.affiliation: Instituto Nacional de Técnica Aeroespacial (INTA), Carretera de Ajalvir Km 4, 28850 Torrejón de Ardoz, Spain. belenguer@inta.es.
authors.forename: Tomás
authors.initials: T
authors.lastname: Belenguer
authors.affiliation: Department of Applied Physics, ETSI Minas, Universidad Politécnica de Madrid, C/Ríos Rosas 21, 28003 Madrid, Spain. felixjose.salazar@upm.es.
authors.forename: Félix
authors.initials: F
authors.lastname: Salazar