TWI Industrial Member Report Summary 499/1994
By G A Georgiou, A M Lank and I J Munns
The wider acceptance of adhesives technology, although used by many sectors of industry (e.g. aerospace, automotive, power generation), has been hindered by the lack of suitable and effective non-destructive testing PDT) methods, particularly at the manufacturing stage. A recent review by TWI, on NDT methods for
adhesively bonded joints, has highlighted that in order to interrogate the joint adequately, it is necessary to use NDT methods which induce non-destructive shear stresses as well as compressive stresses into the joint. In this regard, the review also emphasised the need for theoretical modelling, particularly in the area of ultrasonic NDT. The models have been developed on a workstation, and this approach has proved to be both efficient and cost effective. The workstation provides more direct control and access to the models, than normally available on mainframe computers, and this has played a key role in our efforts to develop computer animations of elastic wave propagation. This report focuses on the use of theoretical modelling of more specialist ultrasonic NDT techniques, such as Rayleigh, Lamb and Stoneley waves. These waves are assessed for their suitability to inspect adhesively bonded joints, and are the means by which shear and compressive stresses are induced into the joint.