Stresses in adhesive joints

General method for assessing resistance of joints to a cyclic laboratory aging environment (moisture and temperature) may use various ASTM standard test geometries 

Method for assessing the effect of stress and moisture and temperature uses a peel joint test 

As above but uses single-lap joints loaded in tension 

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These contradictions can to a considerable degree be resolved by a successfully chosen or properly developed theory of limiting stressed states, with the help of which it should be possible to find an explanation of the discrepancies between design, laboratory, and operating values of breaking stresses in adhesive joints. 

Figure 7.1 Types of stresses in adhesive joints. Adapted from Shields. ...

It has become evident that failure criteria such as maximum shear stress are inadequate since failure can also occur through other modes, such as tensile stresses in adhesive joints. Also, the uncertainty in the stress mode is magnified because properties of and stresses in adhesive joints are highly dependent on joint geometry. Therefore, complexities arise when deciding the proper criterion applicable to designing structural adhesive joints. 

Y. Weitsman, Stresses in adhesive joints due to moisture and temperature, J. Compos. Mater. 11, 368 (1977). 

Sneddon, I., Adhesion. The distribution of stress in adhesive joints. In Eley, D. (Ed.), Chapter 9. Oxford University Press, Oxford, 1961. 

To analyse the stresses in adhesive joints requires a knowledge of the basic engineering properties of the adhesive. Typically, the main properties required are the tensile, or Young s modulus (Ea), the shear modulus (Ga) and the yield... 

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