In the thesis we have reviewed the literature on composites, laminates and light sandwich panels. We learned about three processes of making a very light structural sandwich panels, which we later used in the research with the desire to optimize the manufacturing process. With different parameters we wanted to observe the impact on bending strength and thickness.
The testing was carried out with two core materials, foam and honeycomb, surrounded by a single-layer prepreg carbon fibre fabric on each side. Standard samples were cut out of each series of plates, which were weighed, measured and tested with a three-point bending test. We found that in the range of 0 to 5 bar working pressure in the autoclave gradually reduces the thickness of the sandwich plate. This was particularly pronounced in the samples of foam, which has a less compressive strength than a honeycomb. On the other hand, we found a slight decrease in thickness with an increase in pressure in honeycomb samples, in which case the failure was followed only at the highest pressures. The bending test results were the best of honeycomb at a pressure of 2 bar, and the worst was the panel produced, otherwise with a very commonly used industry process, subsequent gluing. Honeycomb samples also achieved the maximum ratio of bend strength compared to weight. With microscopy, we then wanted to further evaluate the results and found that the most dominant failure in samples glued afterwards is delamination, while in others the combination of core failure and the break of the fibres below the load point.
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