Material and Mechanical Characterizations for Braided Composite Pressure Vessels
Abstract
The materials studied include S-2 glass, carbon, and aramid (Kevlar) fiber reinforced epoxy composites (glass/epoxy, carbon/epoxy, and Kevlar/epoxy, respectively). Twelve material configurations are evaluated. Width-effects determination is conducted to examine the effect of cutting braided specimens from larger panels. Tensile strength and tensile modulus are measured on each material at room temperature and humidity, and on materials conditioned via exposure to a 560 F environment for one second but tested at room temperature and humidity. Resistance to slow and fast heat application (slow and fast cook- off, respectively) is examined to qualitatively determine material response. Additionally, a literature review of hygrothermomechanical effects is conducted. Width effects determination testing shows that as specimen width is increased average tensile strength increases sharply and levels off to a relatively constant value above a specimen width of 2 inches. Thus, the specimen width is set at 2 inches in the tensile test portion of the research. Mechanical property data are presented for the various material configurations. Braid angle is shown to have a strong influence on tensile properties in single-ply braided composites. Single-ply and dual-ply S-2 glass/epoxy composites have higher tensile strength and tensile modulus than their Kevlar/epoxy counterparts of similar configuration. Combining Kevlar/epoxy and carbon/epoxy materials into a composite sandwich significantly improves the tensile properties of Kevlar/epoxy single-ply and dual-ply materials. Only one configuration, a Kevlar/epoxy- carbon-carbon/epoxy-Kevlar/epoxy-steel foil sandwich retained structural integrity for the full fifteen minutes.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1990
- Accession Number
- ADA226640
Entities
People
- Brian K. Antonio
Organizations
- Massachusetts Institute of Technology