Environmental effects and viscoelastic behavior of laminated graphite/epoxy compositesPrimarily because of the polymeric matrix, graphite/epoxy composites are viscoelastic materials which exhibit creep and delayed failures. Guided by the time-temperature superposition principle, the authors are developing accelerated characterization techniques to predict the long term compliance behavior and creep rupture strength of composite materials based on short term tests at elevated temperatures. The effect of a post-cure cycle on the compliance and creep rupture strength of composite materials is discussed. The Zhurkov type failure law is applied to experimental creep rupture data of a typical laminate and is shown to correlate the data. A beneficial mechanical strengthening effect is described which significantly affects the failure strengths of specimens which have been under creep loading for a period of time. This aging effect is reversible if the specimen is allowed to recover before being loaded to failure. Other environmental aspects of composite materials are also reviewed.
Document ID
19840040727
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Dillard, D. A. (Virginia Polytechnic Inst. and State Univ. Blacksburg, VA, United States)
Morris, D. H. (Virginia Polytechnic Inst. and State Univ. Blacksburg, VA, United States)
Brinson, H. F. (Virginia Polytechnic Institute and State University Blacksburg, VA, United States)