Biaxial test results for strength and deformation of a range of E-glass and carbon fibre reinforced composite laminates: failure exercise benchmark data

In Part A of the World Wide Failure Exercise (published in Composite Science and Technology, Vol 58, No 7, 1998), all contributors were given exactly the same set of material properties and were asked to predict the strength and deformation of the same set of laminates under a range of specified loading conditions. In this part (Part B) of the exercise, available experimental results are superimposed on the theoretical predictions and returned to the contributors for comment. The test data were for (a) 0° unidirectional laminae under biaxial direct and shear loads (b) (90°/±30°)s, (0°/±45°/90°)s, (±55°)s multi-directional laminates under biaxial loads and (c) stress strain curves for (0°/±45°/90°)s, (±55°)s, (±45°)s and (0°/90°)s laminates under uniaxial and biaxial loads. This paper briefly describes the experimental results issued in Part B of the Exercise and their origin and limitations. Comments are made on the material properties given for the unidirectional fibre reinforced layers and constituents used in Part A of the Exercise and on approximations in the laminate models specified in Part A. © QinetiQ Ltd. 2002.