Effects of polyethylene and polyurethane Teflon-fillers on the energy absorption behavior of composite tubes during the flattening tests

This article performs an experimental analysis on the E-glass/polyester and vinylester composite tubes with circular cross-section subjected to the lateral compression loading during the flattening process in three different filling conditions: empty, polyethylene, and polyurethane Teflon-filled. Energy absorption behavior and failure response of the composite tubes during the lateral compression tests in the quasi-static condition are studied. The effects of Teflon-type, Teflon-filling, Teflon wall thickness and length, tube inner diameter, fiber fabric layer, and tube length are investigated on the crashworthiness parameters of lateral load, total absorbed energy, and specific absorbed energy (SAE) of the circular composite tubes. The experiments introduce the cylindrical polyethylene Teflon with the large wall thickness as the appropriate filler into the composite tubes, but the experimental measurements show that filling the tubes by the polyurethane Teflon-filler has undesirable effects on the mechanical behavior of the flattened specimens. Also, according to the flattening tests, it is found that in the polyethylene Teflon-filled specimens, the tubes with the vinylester resin have the higher SAE, compared with the corresponding specimens with the polyester resin.