Static axial crush performance of unfilled and foamed-filled composite tubes

Abstract

Abstract. The use and the combination of new, high efficient materials for crashworthiness is of great interest nowadays. Foamed materials are commonly used to increase efficiency of composite materials. Based on the results obtained by Brachos and Douglas, it can be concluded that the sum of the energy absorption capabilities of the foamed filling and unfilled composite tubes is smaller than the energy absorbed by the tubes filled with the same filling. The paper presents the results of the experimental investigations into the influence of filling the tubes with different materials on the impact energy absorption capability. The tube shaped specimens made of epoxy composite, reinforced with carbon or glass fabrics were filled with foamed aluminium or foamed poly(vinyl chloride). It was proved that the foamed materials increase the energy absorption and the absorbed energy of the tubes filled with foams is greater than the sum of the energy absorbed by the composite tube without filling and the foamed material itself investigated separately, when the wall thickness is more than 2 mm. The investigations of the filled tubes with the thickness of walls equal to 1 mm showed lower absorbed energy values because the crushing force had decreased during the crush. The investigations were executed to show what are the effects of filling composite energy absorbing elements in the shape of tubes with foamed materials. Additionally, influence of tube wall thickness and crush mechanism were studied.

The energy-absorbing characteristics of tubular sandwich structures

“…These values are significantly higher than those observed in more traditional sandwich structures. For example, previous studies have reported SEA values of only up to 45 kJ/kg for aluminium honeycomb [34], 5.5 kJ/kg for aluminium foam [17] and 18 kJ/kg for Nomex honeycomb [34]. Finally, the values for the larger diameter tubes are relatively constant across the range of areal densities considered.…”

“…A number of researchers [13–17] have investigated the energy-absorbing characteristics of metal-based foams, such as those manufactured from aluminum alloys. The strain-rate sensitivity of closed-cell aluminium foam specimens in uniaxial compression was investigated by Paul and Ramamurty [13].…”

State‐of‐the‐art review on honeycomb sandwich composite structures with an emphasis on filler materials

“…Ochelski et al [57] analyzed the crushing potential of unfilled and elastomer-filled composite tubular structures. Ochelski et al [58] investigated the performance of unfilled and foam-filled fiber-reinforced tubes. Arbaoui et al [59] evaluated the influence of variations in core thickness and intermediate layers on the mechanical properties of a polypropylene honeycomb core.…”

Load carrying capacity numerical study of I-beam pillar structure with blast protective panel

“…A support pillar is made of I-beam and is loaded by weight of a sur-rounding roof structure, represented by the force P and the lumped mass M. The multilayer protective panel consists of steel, fibre reinforced composite and metallic foam. A choice of such a layout was partially driven by experimental results showing a very good crashworthiness of foam and composites assembled together [13]. It is assumed, that two different phenomena are responsible for minimization of shock wave effects: flow around cylindrical panel and energy absorption by a panel structure.…”