March 2000

March SN Contents

Tech News

Database Coding Standardized for Composite Materials

D 6507, Standard Practice for the Fiber Reinforcement Orientation Codes for Composite Materials, is now available. Adoption of the practice enables consistent recording of material information when designing composite materials with database consultation. By following the orientation codes in ASTM D 6507, independent parties on a project can compare and exchange information accurately despite the use of diverse databases.

“For composite materials, it is very important to be able to identify how the different layers are stacked up,” says Crystal Newton, Ph.D., scientist, University of Delaware Center for Composite Materials, Newark. “For example, there are two different reference systems for angles in composite materials. Depending on which reference system you use, a -45 may be a 135 in a different system. This standard basically sets up or describes a consistent practice for providing that information. Without that, you don’t really know what material you have, so the properties are meaningless.”

ASTM D 6507 establishes orientation codes for continuous-fiber-reinforced composite materials. Orientation codes are explicitly provided for two-dimensional laminates and braids. The laminate code may also be used for filament-wound materials. An added bonus is an included method that presents subscript information in computerized formats that do not permit subscript notation.

The coding in D 6507 was written by stakeholders from industry, government and academia who participate on both the federal Military Handbook 17 Committee, and on an ASTM task group of Subcommittee D30.01 on Editorial and Resource Standards within Committee D30 on Composite Materials.

D 6507 also covers a new process. “What should also be noted is that orientation codes for braided materials have been added,” says Newton, who chairs Subcommittee D30.01. “That is a relatively new area and work from NASA-Langley Research Center was drawn on for that particular area. It’s a case where, with luck, we’ll be ahead of the game. We are setting a standard before a number of practices are established.”

For further technical information, contact Crystal Newton, Ph.D., University of Delaware Center for Composite Materials, Newark, DE 19716 (302/831-1017; 302/831-8525). For committee membership or meeting information, contact D30 Staff Manager Jim Olshefsky, ASTM (610/832-9714). //