Accession Number : AD0747343

Title :   Edge Effects in Angle Ply Composites.

Descriptive Note : Technical rept.,

Corporate Author : ARMY MATERIALS AND MECHANICS RESEARCH CENTER WATERTOWN MASS

Personal Author(s) : Oplinger,Donald W.

Report Date : DEC 1971

Pagination or Media Count : 79

Abstract : Analytical results are presented for stress distribution in fiber-reinforced angle ply laminates under tension to focus attention on the conditions under which interlaminar shear stresses, in the vicinity of free edges, are likely to contribute to failure. The results show how fiber orientation, number of layers, stacking sequence, and structure of the reinforcing elements (yarn- type versus large-diameter filament reinforcement) play a part in determining the level of interlaminar shear stresses encountered when the bar is loaded to failure. The analysis consists of the solution of a system of difference- differential equations, obtained from a discretized form of the three-dimensional elasticity equations, generated by the introduction of thickness averaged stresses and strains in the various layers. The implications of ignoring certain stresses encountered in the exact formulation of the problem are discussed. Closed-form limiting expressions obtained for large numbers of layers give results which appear to be similar, in cases where comparisons can be made, to results obtained from a continuum formulation of the problem using finite difference methods. (Author-PL)

Descriptors :   (*REINFORCED PLASTICS, STRESSES), LAMINATED PLASTICS, FIBERS, REINFORCING MATERIALS, ALIGNMENT

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE