Backing-out composite lamina strengths from cross-ply testing

The issue of cross-ply testing to determine mechanical properties for the characterization of the strength of composite laminates is fundamental to fiber–polymer composites, because experience has shown that this technique leads to more accurate and more representative characterizations for the tensile and compressive strengths of unidirectional composite laminae than those achieved by direct measurement. The indirect analytical method for the evaluation of the tensile and compressive strength of UD laminates at 0° is based on the application of the so-called Back-Out Factor (BF), a multiply factor determined by using the experimental values obtained from tensile and compressive tests on cross-ply specimens.