The Effect of Environment on the Compressive Strengths of Laminated Epoxy Matrix Composites.
Abstract
The program was designed to assess the effects of temperature and absorbed moisture on the static compression behavior of epoxy matrix composites under loading conditions wherein the dominant failure modes are those which occur in structural applications. Compression test fixtures providing varying degrees of geometrical constraint were employed in order to conduct a complete series of column tests ranging from perfectly elastic to fully restrained. Two graphite/epoxy materials were evaluated, T300/5208 and AS/3501-5A. Both longitudinal and transverse orientations of three specimen types, a 0-degree unidirectional, a quasi-isotropic and a 67%-0-degree laminate were evaluated at four temperatures, -54 C (-65 F), 22 C (72 F), 93 C (200 F) and 135 C (275 F) after exposure to one of two environmental conditions: dry, (22 C (72 F) and 40% R. H.) and wet (82 C (180 F) and 90% R.H.). Both materials were characterized under static-tension and shear loading and Tg, thermal expansion and moisture distributions were determined. Analytical procedures for predicting the column buckling behavior under various conditions were developed. Elastic buckling of the laminates investigated were relatively unaffected by moisture and temperature. The inelastic buckling curve revealed a drop due to moisture and temperature which was dependent upon material and laminate type. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1979
- Accession Number
- ADA085167
Entities
People
- K. N. Lauraitis
- P. E. Sandorff
Organizations
- Lockheed Martin