Deriving Composite Lamina Properties from Laminate Properties Using Classical Lamination Theory and Failure Criteria

This paper proposes a method of deriving the engineering and strength properties of unidirectional lamina from laminate properties. Simple straight-sided untabbed tension and compression specimens are used to obtain the laminate properties. The derivation approach is an extension of existing methods that use cross-ply or angle-ply test specimens and back-out factors (also known as cross-ply factors) to derive unidirectional lamina strengths in the fiber direction. This method may reduce the cost of testing and improve the accuracy of strength predictions. It may be used to characterize some newer material forms such as two-dimensional braids.