Initiation and Propagation with Environmental Exposures

Crack Initiation and Propagation with Environmental Exposures 

The fracture mechanics approach to evaluating joint durability basically relates to the early work of Griffith(i 72) in 1920 with brittle materials like glass. IrwinO S) in i960 used the concept to measure a materials resistance to fast crack extension in the presence of a flaw. 

FIGURE 12. Stress-durability curves for aluminum joints with a variety of surface pretreatments when exposed to 100% RH at 52°C. [From J. D. Minford, in Adhesives in Manufacturing (G. L. Schneberger, ed.), Chapter 23, Marcel Dekker, New York (1983).] 

FIGURE 13. Bonded tapered double cantilever beam (TDCB), used for quantitative evaluations of fracture toughness and environmental durability effects on bonded systems. (From Reference 25.) 

Reference should also be made to recent work relating to the failure of joints due to fatigue stressing. Chen, Niem, and have studied the fatigue life of both plastic-to-plastic and 

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