Accession Number : AD0693506

Title :   THE ROTATIONAL TRANSFORMATION OF ELASTIC MODULI FOR FIBER-REINFORCED LAMINAE.

Descriptive Note : Final rept.,

Corporate Author : TEXAS A AND M UNIV COLLEGE STATION DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Ellis,David E. ; Thornton,H. Richard

Report Date : DEC 1968

Pagination or Media Count : 49

Abstract : The current analysis of thin shells laminated from unidirectional fiber-reinforced laminae is based on knowledge of the elastic properties of individual lamina. The elastic properties of the individual lamina are determined through experimentation. The test data are established for the principal directions of the lamina and a tensor based transformation is used to associate with the coordinate system of the shell. The elastic moduli of the laminate are then obtained by an appropriate consideration of the individual lamina properties. Because components designed using the above analysis have not performed as expected, the assumptions involved are being reviewed in search of a more accurate material characterization procedure. The research effort reported here concerns the applicability of the transformation equations to unidirectional fiber-reinforced laminae. These transformation equations are basic to any design or structural analysis concerning laminated materials other than those exhibiting homogenous, isotropic characteristics. The assumptions in question are homogeniety and plane stress. The transformation equations are derived and analyzed to determine applicability. Thin boron fiber reinforced epoxy orientations, are evaluated and correlated with the applicability analysis to establish the validity of the transformation equations. (Author)

Descriptors :   (*SHELLS(STRUCTURAL FORMS), ELASTIC PROPERTIES), (*COMPOSITE MATERIALS, ELASTIC PROPERTIES), (*ELASTIC PROPERTIES, TENSOR ANALYSIS), TRANSFORMATIONS(MATHEMATICS), EXPERIMENTAL DATA, LEAST SQUARES METHOD, TENSILE PROPERTIES, SYNTHETIC FIBERS, LAMINATES, STRESSES

Subject Categories : Laminates and Composite Materials
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE