An overview of corrosion defect characterization using active infrared thermography

Acoustic emission (AE) and infrared thermography (IT) are simultaneously combined to identify damage evolution in carbon fibre reinforced composites. Samples are subjected to tensile static loads while acoustic emission sensors and an infrared camera record the acoustic signals and the temperature variations respectively. Unsupervised pattern recognition procedure is applied to identify damage mechanisms from acoustic signals. Thermodynamic arguments are introduced to estimate global heat source fields from thermal measurements and anisotropic heat conduction behavior is taken into account by means of homogenization technique. A spatial and time analysis of acoustic events and heat sources is developed and some correlation range in the AE and IT events amplitude are identified.

/pdf/damage-detection-in-cfrp-by-coupling-acoustic-emission-and-nhahgsi4w2.pdf

Damage detection in CFRP by coupling acoustic emission and infrared thermography

Polymer composite materials are being increasingly used in primary load-bearing structures in several advanced industrial fields such as aerospace vessels, railway wagons and mega-scaled wind turbines where detection of subcritical damage initiation can significantly reduce safety issues and maintenance costs. It is therefore crucial to inspect these composite structures in order to assess their structural health and to ensure their integrity. Non-destructive testing techniques (NDT) are used for this purpose, making it possible to monitor mechanical damage of composite materials under in situ or ex situ service conditions. This paper reviews the capabilities of the most common NDT techniques used to inspect the integrity of composite materials. Each technique has a detection potential and cannot allow a full diagnosis of the mechanical damage state of the material. Thus, depending on the occurring damage mechanism and the conditions of use, one technique will be preferred over another, or several techniques should be combined to improve the diagnosis of the damage state of the structures.

A review of non-destructive techniques used for mechanical damage assessment in polymer composites

Cluster analysis of acoustic emission signals and deformation measurement for delaminated glass fiber epoxy composites

The use of intelligent computational tools for damage detection and identification with an emphasis on composites – A review

https://hal.archives-ouvertes.fr/hal-01269665/document

Heat source estimation in anisotropic materials

Improvement of the design and reliability of aeronautical composite structures requires an identification and characterization of their damage evolution. By providing surface thermal fields, infrared thermography has allowed considerable progress in the detection of degradation phenomena. On the other hand, acoustic emission is employed to record the transient waves resulting from released energy during a damage process. This study intends to combine simultaneously these nondestructive methods to investigate the damage behaviour of carbon-fibre composites under tensile load. Experimental results show some correlations between thermal and acoustic events induced by the load according to the damage development.

/pdf/coupling-infrared-thermography-and-acoustic-emission-for-2cw00vna4m.pdf

Coupling infrared thermography and acoustic emission for damage study in CFRP composites

Experimental & numerical study of the Tensile/Compression-Shear Arcan test under dynamic loading

Nowadays, adhesively bonded structures are widely used in the transport sector for the development of lightweight vehicles. In order to guarantee passenger safety, it is thus necessary to understand the behaviour of such assemblies under dynamic and combined loadings. This paper presents a numerical study of the local behaviour of adhesively bonded assemblies under dynamic loading. In a first part, the ASTM D950-03 block impact test is studied. This device does not enable an homogeneous loading of the adhesive and causes stress concentrations. On the basis of existing quasi-static works, strategies are then implemented at a local scale. By combining a specific substrates geometry and by limiting the stiffness gradient between the substrates and the adhesive, results show that it is possible to obtain a qualitatively acceptable stress fields in the adhesive for mechanical characterization under dynamic loadings. The Arcan TCS device mentioned below, uses such solutions to characterize the mechanical behaviour of bonded joints subjected to combined quasi-static loadings. In this study, the question of its extensibility to dynamic loadings by the use of an impactor guided into a drop tower is investigated. A dedicated finite element model is built under the plane stress assumption. The stress distributions in the adhesive are analysed through time and space for several loading conditions. The stress versus time signals are then compared with the results coming from modal analysis in order to highlight the vibration behaviour of the device, directly linked to the configuration.

/pdf/numerical-study-of-the-local-behaviour-of-adhesive-bonds-4ny5xx8m4a.pdf

Benjamin Vales

Papers

Damage detection in CFRP by coupling acoustic emission and infrared thermography

Heat source estimation in anisotropic materials

Coupling infrared thermography and acoustic emission for damage study in CFRP composites

Experimental & numerical study of the Tensile/Compression-Shear Arcan test under dynamic loading

Numerical study of the local behaviour of adhesive bonds under dynamic loading