Zuluaga Ramírez, PabloFrövel, MalteBelenguer Dávila, TomásSalazar, Felix2023-06-182023-06-182015-11-111996-194410.3390/ma8115407https://hdl.handle.net/20.500.14352/23066Received: 18 September 2015 / Accepted: 30 October 2015 / Published: 11 November 2015 Este artículo pertenece al Número Especial: "Failure analysis in materials".This work presents an optical non-contact technique to evaluate the fatigue damage state of CFRP structures measuring the irregularity factor of the surface. This factor includes information about surface topology and can be measured easily on field, by techniques such as optical perfilometers. The surface irregularity factor has been correlated with stiffness degradation, which is a well-accepted parameter for the evaluation of the fatigue damage state of composite materials. Constant amplitude fatigue loads (CAL) and realistic variable amplitude loads (VAL), representative of real in- flight conditions, have been applied to “dog bone” shaped tensile specimens. It has been shown that the measurement of the surface irregularity parameters can be applied to evaluate the damage state of a structure, and that it is independent of the type of fatigue load that has caused the damage. As a result, this measurement technique is applicable for a wide range of inspections of composite material structures, from pressurized tanks with constant amplitude loads, to variable amplitude loaded aeronautical structures such as wings and empennages, up to automotive and other industrial applications.engAtribución 3.0 Españahttps://creativecommons.org/licenses/by/3.0/es/journal articlehttp://dx.doi.org/10.3390/ma8115407http://www.mdpi.com/1996-1944/8/11/5407open access620.1629.7fatigue damagecomposites materialsCFRPnon-destructive testnon-contact inspectionoptical inspectionspectrum fatigue loadsirregularity factorAeronáuticaFísica de materiales3301 Ingeniería y Tecnología Aeronáuticas