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An experimental study about the application of vibrothermography for the investigation of multiple microcracking in woven composites is here reported. The material is first damaged during tensile loading tests in order to have samples that present increasingly damaged states. The goal of the study is to apply vibrothermography to compare the sensitivity of their heating behaviour (global and local) with the crack density. A correlation between the heating and the loss of a mechanical property of the material (in this case the Young modulus) estimated with the tensile loading tests is also highlighted.

The Flexural properties and Scanning electron Microscope analysis of Bamboo/glass fibersReinforced epoxy Hybrid composites were studied. The effect of alkali treatment of the bamboo fibers on these properties was also studied. It was observed that flexural properties of the hybrid composite increase with glass fiber content. These properties found to be higher when alkali treated bamboo fibers were used in the hybrid composites. The elimination of amorphous hemi-cellulose with alkali treated leading to higher crystallinity of the bamboo fibers with alkali treatment may be responsible for these observations. The author investigated the interfacial bonding between Glass/Bamboo reinforced epoxy composites. The effect of alkali treatment on the bonding between Glass/Bamboo composites was also studied.

Fatigue dimensioning of composite structures has become a great challenge in the aeronautic industry. The estimation of the fatigue limit requires time-consuming experimental campaigns: millions of mechanical cycles are applied to one studied sample until failure, for several load levels. The alternative discussed in the present paper is to monitor the self-heating of carbon/epoxy composites under a significantly reduced number of load cycles, in order to define fatigue damage indicators. The chosen approach is to use lock-in thermography, which makes it possible to analyse the first harmonics of the heating signal, not matter how noisy it might be.