Advanced composites project engineer, Grumman Corporation, Bethpage, NY
Pages: 25 Published: Jan 1989
A method is presented here wherein the lamina test data, which is usually more readily available and is, in any event, less costly to obtain, is statistically reduced to provide (1) B basis material properties for tension, compression, and shear and (2) population variability for the particular failure mode and environment. This information is then combined with average laminate and joint data to obtain design allowables. The feasibility of this approach is illustrated using material test data generated at the lamina and laminate level for a secondary structure on a commercial aircraft.
The following ASTM test methods, ASTM Test Method for Tensile Properties of Plastics (D 638), ASTM Test Method for Compressive Properties of Rigid Plastics (D 695), ASTM Test Method for Apparent Interlaminar Shear Strength of Parallel Fiber Composites by Short Beam Method (D 2344), ASTM Test Method for Tensile Properties of Fiber-Resin Composites (D 3039), and ASTM Test Method for Compressive Properties of Unidirectional or Crossply Fiber-Resin Composites (D 3410) were utilized to generate lamina test data. The adequacy of these test meth-ods to provide meaningful data is also discussed.
composite materials, graphite/epoxy, design allowables, lamina tests, laminate tests, statistics
Paper ID: STP10023S