eesti teaduste
akadeemia kirjastus
Proceedings of the Estonian Academy of Sciences. Physics. Mathematics

Propagation of delamination zones in bonded joints; 170–176

Full article in PDF format

Juan Pablo Casas-Rodriguez, Ian A. Ashcroft, Vadim V. Silberschmidt


Delamination is one of the main failure mechanisms in bonded composite joints. Owing to a considerable spatial scatter in adhesion over the interface in such joints, initiation of a delamination zone and propagation of its front are highly random processes. The main delamination front is rather tortuous, and many small delamination spots are formed in its immediate vicinity. These processes can be additionally complicated in the case of loading types such as fatigue and/or multiple impacting. This paper deals with experimental methods of analysing delamination zones at various stages of their evolution. X-radiographs of delamination zones are digitalized and scaling analyses based on fractal and multifractal approaches are performed in order to quantify the morphology as well as the damage distribution in the immediate vicinity of delamination fronts.

1. Ashcroft, I. A, Erpolat, S. and Tyrer, J. Damage assessment in bonded composite joints. Key Eng. Mater., 2003, 245–246, 501–508.

 2. Casas-Rodriguez, J. P., Ashcroft, I. A. and Silberschmidt, V. V. Effects of impact fatigue in the damage propagation in adhesive joints of CFRP. Comp. Sci. Techn. (in press).

3. Casas-Rodriguez, J. P., Ashcroft, I. A. and Silberschmidt, V. V. Damage evolution in adhesive joints subjected to impact fatigue. J. Sound Vib. (in press).

4. Ashcroft, I. A. A simple model to predict crack growth in bonded joints and laminates under variable-amplitude fatigue. J. Strain Anal., 2004, 39, 707–716.


5. Silberschmidt, V. V. Dynamics and scaling characteristics of shear crack propagation. Pure Appl. Geophys., 2000, 157, 523–538.


6. Silberschmidt, V. V. Effect of material’s randomness on scaling of crack propagation in ceramics. Int. J. Fracture, 2006, 140, 73–85.

7. Feder, J. Fractals. Plenum Press, New York, 1988.

8. Harte, D. Multifractals: Theory and Applications. Chapman & Hall/CRC, Boca Raton, 2001.

9. Silberschmidt, V. V. On the multifractal character of load distribution near the cracks. Europhys. Lett., 1993, 23, 593–598.

Back to Issue