Progressive failure of CFRP tubes reinforced with composite sandwich panels: Numerical analysis and energy absorption

Abstract This study investigates a novel CFRP tube by reinforced with composite sandwich panels (CSPs) for enhanced energy absorption. First, CSP-reinforced CFRP tubes with the ply sequence [0 3/902/03 /(0/90)] were manufactured via bottom confinement using epoxy adhesives and then subjected to a 2 mm/min quasi-static compression. Then, numerical models were developed, based on the continuum damage mechanic for intralaminar failure and the cohesive zone method for interlaminar damage of CFRP materials with an elastic–plastic model for honeycombs, to predict the progressive failure of the composite tubes. Finally, the numerical results were validated with experimental study of tubes’ energy absorption and failure mechanisms. The experiments showed that the total energy absorption and crushing force efficiency of the CSP-reinforced CFRP tubes were 37% and 24% greater, respectively, than those of unreinforced CFRP tubes, although the corresponding specific energy absorption exhibited a slight decrease of 1%, demonstrating an overall improvement in energy absorption of the proposed composite tube. Moreover, the presented numerical models exhibited the primary damage behaviours and were used to evaluate the crushing performance of these composite tubes as validated by the experimental results, providing a new available approach for predicting the progressive failure of composites with different layer types (i.e. unidirectional, woven) and composite structures with complex constituents (laminate, honeycomb). Lastly, an efficient predictive approach was developed for designing CSP-CFRP tubes for engineering energy-absorption applications.