Review and comparison of shearography and pulsed thermography for adhesive bond evaluation

Hung, Michael Y. Y.; Chen, Yun Shen; Ng, Siu Pang; Shepard, Steven M.; Hou, Yanan; Lhota, James R.

doi:10.1117/1.2741277

Cited by 53 publications

(25 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…GLARE panels, honeycomb structures and glass (or carbon)-fibre-reinforced plactics [26]. Other shearography applications are measurement of specific surface strains, residual stresses, 3D shapes and vibration modes, and leakage detection [14]. All these applications have in common, that the samples are usually static.…”

Section: Shearographymentioning

confidence: 99%

“…Traditional ultrasound longitudinal and shear bulk waves [7][8][9], as well as more recently Lamb or Shear-Horizontal (SH) guided waves [10][11][12] are ultrasound techniques that get increasingly applied to inspect the bond of multi-layered bonds. Shearography [13][14][15] and Thermography [15][16][17][18] are innovative optical techniques that allow full-field, non-contact and speedy detection in composite materials. However, no research papers were published on the application of these NDT techniques to Al-Sn alloy/steel bimetal strip that was manufactured in the CRB process.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A feasibility study on different NDT techniques used for testing bond quality in cold roll bonded Al-Sn alloy/steel bimetal strips

2017

View full text Add to dashboard Cite

-This paper presents non-destructive testing (NDT) results for the detection of bond defects in aluminiumtin (Al-Sn) alloy/steel bimetal strips. Among all types of bimetal strip that are used in the automotive industry for plain journal engine bearings, Al-Sn alloys cold roll bonded (CRB) onto steel backing is the most common type. The difficulty to evaluate the metallurgical bond between the two dissimilar metals is a major industrial concern, which comprises the risk that bearings fail in the field. Considering the harsh performance requirements, 100% online non-destructive testing would be desirable to significantly reduce the business risk. Nowadays bimetal strip manufacturers still rely on destructive testing through different peel-off tests. This work offers the results from four independent NDT studies, using active thermography, shearography, ultrasound and guided wave electromagnetic acoustic transducers (EMATs) and samples with different artificially implanted defects, to explore the feasibility to qualitatively indicate the occurrence of bond defects. A destructive peel off test was used to correlate the NDT results with known bond quality. The studies were done under laboratory conditions, and in case of ultrasound also online under production conditions. During the ultrasound online test, the requirements that a NDT technique has to fulfil for online inspection of Al-Sn alloy/steel bimetal strip were established. For active thermography, shearography and guided wave EMAT techniques, it was theoretically analysed, if the laboratory test results could be transferred to testing under production conditions. As a result, guided waves using EMATs, among the four tested methods, are best suited for online inspection of Al-Sn alloy/steel bimetal strip. This research was carried out in collaboration with MAHLE Engine Systems UK Ltd., an Al-Sn alloy/steel bimetal strip manufacturer for the automotive industry.

show abstract

Section: Shearographymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A feasibility study on different NDT techniques used for testing bond quality in cold roll bonded Al-Sn alloy/steel bimetal strips

2017

View full text Add to dashboard Cite

show abstract

“…Shearography has been used for identification of defects in adhesive joints in materials including aluminium and CFRP using flat bottom hole defects in the bond lines [19]. Shearography is able to identify a range of defects including inserts and adhesive starvation in adhesive bonds in rubber, CFRP and ceramics [20].…”

Section: Nde Of Adhesive Bondsmentioning

confidence: 99%

Infrared Techniques for Practical Defect Identification in Bonded Joints in Liquefied Natural Gas Carriers

2017

View full text Add to dashboard Cite

A robust and reliable method for the identification of defects in adhesively bonded joints used in the membrane containment system used to store liquefied natural gas during transport on board ships is required. The adhesively bonded interface of the membrane system may contain low volume defects known as kissing defects, which are extremely difficult to detect using portable inspection techniques. A novel methodology for detecting such defects is described in the paper. To demonstrate the approach simulated kissing defects were produced in a controlled fashion in a representative secondary membrane bond using silicon grease contamination. The defects were detected using an active thermographic approach known as pulsed phase thermography (PPT) which detects subsurface defects by monitoring the effect they have on the propagation of heat through a component. Due to the low volume of kissing defects, they generally have minimal effect on the heat propagation, so the detection was made possible by application of a small load generated by application of a vacuum. The vacuum can be set-up using a reusable chamber and a standard vacuum pump and therefore is portable and can be applied on-site and in a shipyard during construction.

show abstract

“…Thermographic techniques have the advantage of being full field, noncontact and fast. Previous studies have shown the potential use of thermography for identification of defects in adhesive bonds [12]. Most studies have focussed on specific applications or specific material or joint configurations.…”

Section: Introductionmentioning

confidence: 99%

Modelling and evaluation of pulsed and pulse phase thermography through application of composite and metallic case studies

Waugh

Dulieu-Barton

Quinn

2014

NDT & E International

View full text Add to dashboard Cite

Results show PPT to be advantageous over PT due to its deeper probing as it is less influenced by surface features. Whilst UT is able to reveal all the defects in these case studies, the time consuming nature of the process is a significant disadvantage compared to the full field thermography methods. Overall, the model has achieved good correlation for the case studies considered and it was found that the main limiting factor of the PT model accuracy was knowledge of thermal material properties such as conductivity and specific heat. Where these properties were accurately known the model performed very well in comparison with experimental results. PPT modelling performed less well due to the method of processing the PT data which aims to emphasise small differences. Hence inaccuracies in inputted values such as material properties have a much greater influence on the modelled PPT data. The model enables a better understanding of PT and PPT and provides a means of establishing the experimental set-up parameters required for different components, allowing the experimental technique to be appropriately tailored to more complex situations including bonded joints or structures where several materials are present.The paper ends with a section on defect detectability based on thermal diffusivity contrast between the defect and the bulk material. It shows that in aluminium, because of its higher conductivity, greater thermal contrast is achieved for small differences in diffusivity. Regions where the diffusivity ratio between defect and bulk materials was insufficient to provide thermal contrast for defect identification were found. PPT phase data is shown to reduce the extent of such regions increasing the detectability of defects.Effusivity is introduced as a means of determining the thermal contrast between the defect and non-defective areas and hence establishing the defect detectability.

show abstract

Review and comparison of shearography and pulsed thermography for adhesive bond evaluation

Cited by 53 publications

References 21 publications

A feasibility study on different NDT techniques used for testing bond quality in cold roll bonded Al-Sn alloy/steel bimetal strips

A feasibility study on different NDT techniques used for testing bond quality in cold roll bonded Al-Sn alloy/steel bimetal strips

Infrared Techniques for Practical Defect Identification in Bonded Joints in Liquefied Natural Gas Carriers

Modelling and evaluation of pulsed and pulse phase thermography through application of composite and metallic case studies

Contact Info

Product

Resources

About