EXPERIMENTAL VERIFICATION OF IN-PLANE STRESS CALCULATION OF THIN COMPOSITE PLATE BASED ON THE FINITE ELEMENT METHOD

The paper presents a realistic basis for performing an experimental verification of the material strength theory of a composite plate exposed to plane stress. Logical theoretical relations for calculating parameters for the sake of comparison to experimental results are given. A reliable measuring and testing system with a technology for acquisition of experimental data is used. On the basis of an identical given model for the calculation and experimental verification of theoretical results, the parameters are calculated, then measured and compared. The results show a good level of accordance and maintain a satisfying level of accuracy of the applied theory. Some results have shown dispersion, mainly with measured displacements in the normal direction to the loading axis. The final evaluation of the theory requires the calculation to be carried out with correct real values of mechanical characteristics. Since the correction factors for elastic mechanical characteristics of composite materials, that appear as a consequence of specific manufacture (possible defects include: de-lamination, broken fibres, material nonhomogeneity), are in the range 1.2 to 1.4, depending on the composite type, we can assume that the obtained results are within acceptable limits. This may confirm the sustainability of the presented structural analysis theory of composites with linear elastic behaviour.