Composite panels containing multiple through-the-width delaminations and subjected to compression. II: Experiments & verification

The objective of this investigation was to perform compression tests on laminated composites for verifying the analytical model and the finite element analysis previously developed by the authors for analyzing compression response of composite panels containing multiple delaminations. T300/976 graphite/epoxy composite was selected for the study. Specimens with various ply orientations were fabricated from both flat and cylindrical composite panels containing 1-2 pre-implanted through-the-width delaminations. Specimens were tested by uniaxial compression, and strain gauges were utilized to record the strain history as a function of the applied load from initial loading to final failure. Numerical simulations were performed according to the test conditions. Comparisons were then made between the predictions and the measured test data. Overall, the predictions agreed with the data very well. Parameteric studies were also performed using the finite element analysis to demonstrate the effect of the size, location and number of the delaminations on the compression response of laminated composites.