A height-tapered double cantilever beam specimen was introduced for the study of loading rate effects on Mode I delamination fracture toughness of graphite/epoxy composite. The material investigated was AS4/3501-6 graphite/epoxy. Continuous records were obtained of the load, deflection, and crack extension for determination of the strain energy release rate. The latter was calculated by the beam analysis method extended to include the effects of transverse shear and kinetic energy. It was found that the strain energy release rate increases with crack velocity up to a value of approximately 1 m/s (2360 in./min); thereafter, it decreases with increasing crack velocity. The maximum value of the strain energy release rate was approximately 46% higher than the quasi-static value.
|Original language||English (US)|
|Number of pages||18|
|Journal||ASTM Special Technical Publication|
|State||Published - Dec 1 1988|
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