Improvements in the lateral crushing behavior of syntactic foam‐filled glass fiber reinforced polymer tubes by the addition of straight and helical multiwalled carbon nanotubes

Abstract To diminish the brittleness of glass fiber reinforced polymer tubes and syntactic foams, a novel composite tube filled with syntactic foam was proposed, in which thin‐walled tubes were reinforced by ribs and the syntactic foam core reinforced with multiwalled carbon nanotubes (MWCNTs). The influence of the ribs and the type and content of MWCNTs on the lateral crashworthy characteristics of composite tubes was investigated. Crushing experimental results indicated that the ribs contributed to improving the crashworthy performance for both hollow and foam‐filled tubes. The effect of the ribs on the energy absorption was more pronounced for the hollow tubes. Incorporation of straight or helical MWCNTs lead to improvement of the crush resistance and energy absorption for foam‐filled tubes. With the same MWCNT content, the peak load and absorbed energy of specimens with helical MWCNTs were nearly 14% and 13% higher than those of specimens with straight MWCNTs, respectively. Furthermore, analytical models were proposed to predict the load–displacement responses for foam‐filled tubes in the linear‐elastic, postcrushing, and foam‐compaction stages. The predicted results agreed well with experimental results. The resulting composite tubes are potential light‐weighted and crashworthy structures, which could be applied as collapsible energy absorbers in engineering fields.