The components of a hybrid laminate, for example glass fiber reinforced plastic (GFRP) and high strength steel, may exhibit different magnitudes of their thermal expansion coefficients, so that thermally activated residual stresses occur at room temperature. These residual stresses might have a negative effect on the durability of the hybrid material so that an analysis of the residual stresses is needed.
The residual stress analysis has been conducted by means of x-ray diffraction using a sin²-psi method. A hybrid laminate made up by fiber reinforced plastics and steel has been in-vestigated in order to describe the impact of temperature, materials, and volume fraction on the state of the residual stress.
Since glass fibers are absorbing the x-rays, here carbon and aramid fibers are utilized. Three kinds of specimens with different material combinations and laminate designs have been measured and analyzed by x-ray diffraction. The results are compared to an analytical model which predicts the thermal residual stress of a hybrid laminate at room temperature. The re-sults of the measurements correlate well with the results of the analytical model for the here considered hybrid laminates.