The Fifth Conference on Composite Materials: Testing and Design was held 20-22 March 1978 at New Orleans, La. The American Society for Testing and Materials' Committee D30 on High Modulus Fibers and Their Composites sponsored the conference. S. W. Tsai, Air Force Materials Laboratory, served as conference chairman and editor of this publication. Most of the papers presented are included in this volume which complements the first, second, third, and fourth conference publications—ASTM STP 460, ASTM STP 497, ASTM STP 546, and ASTM STP 617, Composite Materials: Testing and Design.