Effects of winding angle on quasi-static axial and lateral crushing behaviour of Carbon Fibre-Reinforced Plastic (CFRP) - filament winding hexagonal tubes

This thesis presents the results of a quasi-static experiment of crushing behaviour for Carbon Fibre-Reinforced Polymer (CFRP) hexagonal tubes in axial and lateral compression loads, whereby the fabrication in a wet-filament winding technique provided a high geometrical accuracy, constant fabrication quality, and relatively high fibre volume fractions. Moreover, in order to improvise the crushing behaviour of energy absorption tube, the filament winding technique of fabrication was applied to provide the final progressive crushing that had withstand the collapsible tubes in one piece and was still intact at the final crushing phase without breaking apart into debris or fragments, which would increase the energy absorption value and the crushing performance of CFRP energy absorbing tube. The behaviour of energy absorbing CFRP tube destruction was examined through experimental quasi-static axial and lateral compression loads to obtain the collapse and crushing modes for CFRP tube. Three hexagonal CFRP tubes from the winding orientation angles of 30°, 45°, and 80° were fabricated from the wet-filament winding technique to determine the local failure effects, which were also able to assess the pattern of destruction for CFRP hexagonal tube at every change of compression load value. Energy absorbed by CFRP hexagonal tube was recorded, while static image at each effect of compression loads reflected the behaviour of energy absorber tubes. There were three main phases in the experiment of quasistatic compression load:
1) The pre-crush phase where the tube was compressed below 30% of the original height of the tube, followed by a maximum compression load at a local peak load point.
2) The third phase was a post-crush phase, defined as compression at the height of the tube under 50%; and
3) The final phase was a compression load at the maximum displacement of 80% from the height of the tube.
The results of the experimental data showed the differences in behaviour of CFRP tubes in three winding orientations and the total amount of energy absorption at each orientation and collapse mode which occurred in quasi-static compression loads had been slightly similar for the three winding orientation tubes. The collapsible mode in the final crushing phase showed that the crushing tubes were still intact in their original forms without breaking into small or large fragments. Overall, the winding tube of 45° orientation for energy absorber tubes showed the best failure mode in the folding mechanism produced high values of energy absorbing in axial and lateral compression loads. Besides, the experimental test data obtained from this study were also expected to be used as references in advanced research related to such structures like honeycomb sandwich panels or energy absorbing structures in the fields of automotive, aerospace, and many others.