Testing of adhesive bonds

Adhesive tests are used for a variety of reasons including  

Testing is important in all aspects of materials science and engineering, but it is especially so in adhesives. Such tests evaluate not only the inherent strength of the adhesive, but also the bonding technique, surface cleanliness, effectiveness of surface treatments, etchings of surfaces, application and coverage of the adhesive, and the curing cycle. 

This chapter hrst discusses in a general manner the various types of testing carried out in adhesive joints. Only the more important types are covered. Following this discussion, a compilation of 53 subject areas is listed, with all relevant ASTM methods and practices and SAE Aerospace Recommended Practices (ARPs). Chapter 12 provides fairly detailed discussions of the contents of each method or practice, with two exceptions. 

Shear tests are very common because samples are simple to construct and closely dupUcate the geometry and service conditions for many structural adhesives. As with tensile tests, the stress distribution is not uniform and, while it is often conventional to give the failure shear stress as the load divided by the bonding area (Table 11.1), the maximum stress at the bond line may be considerably higher than the average stress. The stress in the adhesive may also differ from pure shear. Depending on such factors as adhesive thickness and adherend stiffness, the failure of the adhesive shear joint can be dominated by either shear or tensioa  

Compression shear tests are also commonly used. ASTM D2182 (withdrawn 1983) describes sample geometry similar to the lap-shear specimen 

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Anderson, G. P. Analysis and Testing of Adhesive Bonds Academic ... 

Anderson, G. P. Bennett, S. J. DeVries, K. L. "Analysis and Testing of Adhesive Bonds" Academic Press New York, 1977. 

Gagliano, J. M., "An Improved Method for the Fracture Cleavage Testing of Adhesively-Bonded Wood," Wood Science and Forest Products. Virginia Tech, Blacksburg, VA. 2001. 

G. P. Anderson, S. J. Bennett, and K. L. DeVries, Analysis and Testing of Adhesive Bonds, Academic Press, New York, 1981. 

Analysis of interfaces between materials, especially for failure analysis after aging and testing of adhesively bonded systems Study of the cure of adhesives. 

Rokhlin SI, Marom D. Nondestmctive testing of adhesively bonded joints. J Acoust Soc Am 1990 87(2) 532-42. 

Improvements in Ultrasonic Testing of Adhesive Bonds using the Wavelet Packet Transform (S. Tavroul and C. Jones, eds.), School of Engineering and Science, School of Mathematical Sciences, Swinburne University of Technology, Melbonme, Australia, 2006. 

Adams, R.D. and B.W. Drinkwater, Non-destructive testing of adhesively-bonded joints. International Journal of Materials and Product Technology, 14(5/6), 1999. 

Rose, J.L. and J.J. Ditri, Pulse-echo and through transmission Lamb wave techniques for adhesive bond inspection. British Journal of NOT, 34(12), 1992. GogUo, L. and M. Rossetto, Ultrasonic testing of adhesive bonds of thin metal sheets. NDT E International, 32 323-331,1999. 

Fig. 1. Comparison of destructive shear strength tests on laminates with the predicted strengths using a Fokker bond tester. A series of laminates is represented where the adherend thickness t varies as follows ( ), t = 0.6 mm (O), t = 0.8 mm (x), f = 1.0 mm (-h), f = 1.2 mm (A), t = 1.5 mm. To construct this standard plot, 120 specimens of Dural 2024-T3 were used 95% of all results are within the range 0.36 kg mm . (From R J Schliekelmann, Non-destructive testing of adhesively bonded joints, in Adhesion, Fundamentals and Practice, McClaren, London, 1966)...

Many widely used Tests of adhesion can be applied to the rubber to metal bonds Blister test. Fracture-mechanics test specimens. Non-destructive testing of adhesively-bonded structures. Peel tests. Shear tests. Tensile tests and Wedge test. This particular article is concerned with those aspects that are of practical concern in the rubber-processing industry. 

Non-destructive testing of adhesively-bonded structures G J CURTIS Acoustic wave techniques, resonance and pulse-echo testers... 

E. Segal and J. L. Rose, Nondestructive testing of adhesive bond joints, in Research Techniques in Nondestructive Testing, Vol. IV (R. S. Sharpe, ed.), Chapter 8, Academic Press, London (1980). 

T. Chemobelskays, S. Kovnovich, and E. Hamik, The testing of adhesive bonded joints by a very high-resolution ultrasonic probe, J. Appl. Phys. 12, 815 (1979). 

R. J. Schliekelmann, Nondestructive testing of adhesive bonded joints, Fokker-VFW Technical Report, NTIS (N81-28190), 38 pp. (April, 1982). 

G. J. Curtis, Nondestructive testing of adhesively bonded structures with acoustic methods. Ultrasonic Testing Non-Conventional Testing Techniques, pp. 495-554 (1982). 

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