A novel corrugated carbon-fiber composite tube with circular corrugations on the lateral surface for crashworthiness: Manufacturing method, experimental and numerical analysis

Abstract

A novel design and method of manufacture of laterally corrugated composite tube is proposed. One of the main issues with studying such corrugated composite tubes has been taking out the mandril from the composite specimens, leading to very little, if any, experimental research into this subject. Therefore, as the main novelty of this paper, a multi-step process has been thoroughly explained to overcome these manufacturing challenges, i.e., the use of ABS corrugated mandrels, silicone molds, wax mandrels, filament winding, and finally heating the wax mandrel to melt. At the end of this process, the lateral corrugated composite tube is obtained. There are two different types of specimens: conical corrugated composite tube and cylindrical corrugated composite tube. From each category, two specimens are tested, whose crashworthiness results are then compared with one another to see which design offers better energy absorption capacity. Subsequently, using the experimental data, a finite element model is developed and validated to numerically look into the effect of number of corrugations on the crashworthiness of the structures. To do so, the specific energy absorption (SEA), peak force, mean force, and crushing force efficiency (CFE) of each model have been compared with one another. It is understood from both experiments and numerical study that the conical composite tubes offer better crashworthiness as they can absorb more energy and maintain a higher mean force than the cylindrical ones. For instance, in the experiments, it was observed the conical corrugated composite tube had an SEA of 12.37 kJ/kg, while this value for cylindrical one was 8.38 kJ/kg. Moreover, with an increase in the number of corrugations within a set length for the tube, the energy absorption capacity of the structure can be increased. To provide a better understanding of the observation, with an increase in the number of corrugations from 12 to 18, SEA increased from 9.21 to 12.43 kJ/kg in the cylindrical models, and from 10.80 to 13.01 kJ/kg in conical ones.