A review of thermographic techniques for damage investigation in composites

The aim of this work is a review of scientific results in the literature, related to the application of thermographic techniques to composite materials. Thermography is the analysis of the surface temperature of a body by infrared rays detection via a thermal-camera. The use of this technique is mainly based on the modification of the surface temperature of a material, when it is stimulated by means of a thermal or mechanical external source. The presence of defects, in fact, induces a localized variation in its temperature distribution and, then, the measured values of the surface temperature can be used to localize and evaluate the dimensions and the evolution of defects. In the past, many applications of thermography were proposed on homogeneous materials, but only recently this technique has also been extended to composites. In this work several applications of thermography to fibres reinforced plastics are presented. Thermographic measurements are performed on the surface of the specimens, while undergoing static and dynamic tensile loading. The joint analysis of thermal and mechanical data allows one to assess the damage evolution and to study the damage phenomenon from both mechanical and energetic viewpoints. In particular, one of the main issues is to obtain information about the fatigue behaviour of composite materials, by following an approach successfully applied to homogenous materials. This approach is based on the application of infrared thermography on specimens subjected to static or stepwise dynamic loadings and on the definition of a damage stress, ?D, that is correlated to the fatigue strength of the material. A wide series of experimental fatigue tests has been carried out to verify if the value of the damage stress, ?D, is correlated with the fatigue strength of the material. The agreement between the different values is good, showing the reliability of the presented thermographic techniques, to the study of composite damage and their fatigue behaviour.

[1]  Janice M. Dulieu-Barton,et al.  A temperature correction methodology for quantitative thermoelastic stress analysis and damage assessment , 2006 .

[2]  Xavier Maldague,et al.  Theory and Practice of Infrared Technology for Nondestructive Testing , 2001 .

[3]  T. Keller,et al.  Tensile fatigue performance of pultruded glass fiber reinforced polymer profiles , 2005 .

[4]  G. Minak.  On the Determination of the Fatigue Life of Laminated Graphite-Epoxy Composite by Means of Temperature Measurement , 2010 .

[5]  L. Vergani,et al.  Damage assessment of composite materials by means of thermographic analyses , 2013 .

[6]  P. Cunningham,et al.  A generalised approach to the calibration of orthotropic materials for thermoelastic stress analysis , 2008 .

[7]  Ramesh Talreja,et al.  Fatigue damage mechanisms in unidirectional carbon-fibre-reinforced plastics , 1999 .

[8]  R. Rowlands,et al.  Thermoelastic Stress Analysis , 2008 .

[9]  P. Stanley,et al.  The application of thermoelastic stress analysis techniques to composite materials , 1988 .

[10]  L. Vergani,et al.  Fatigue damage in GFRP , 2012 .

[11]  J. Dulieu‐Barton,et al.  Progress in Thermoelastic Residual Stress Measurement , 2004 .

[12]  Chiara Colombo,et al.  INFLUENCE OF DELAMINATION ON FATIGUE PROPERTIES OF A FIBREGLASS COMPOSITE , 2014 .

[13]  William Thomson,et al.  II. On the thermoelastic, thermomagnetic, and pyroelectric properties of matter , 1878 .

[14]  G. Risitano,et al.  A first approach to the analysis of fatigue parameters by thermal variations in static tests on plastics , 2010 .

[15]  Claude Bathias,et al.  An engineering point of view about fatigue of polymer matrix composite materials , 2006 .

[16]  Antonino Risitano,et al.  Thermographic methodology for rapid determination of the fatigue limit of materials and mechanical components , 2000 .

[17]  John Montesano,et al.  Use of infrared thermography to investigate the fatigue behavior of a carbon fiber reinforced polymer composite , 2013 .

[18]  Chiara Colombo,et al.  Static and fatigue characterisation of new basalt fibre reinforced composites , 2012 .

[19]  Otwin Breitenstein,et al.  Lock-in thermography : basics and use for functional diagnostics of electronic components , 2003 .

[20]  Janice M. Dulieu-Barton,et al.  Thermoelastic stress analysis of damage mechanisms in composite materials , 2010 .

[21]  P Stanley,et al.  Development and applications of thermoelastic stress analysis , 1998 .

[22]  Eric Chesmar,et al.  Care and Repair of Advanced Composites , 1997 .