The Study on the Crush Characteristic of Polyurethane Foam-filled Rectangular Steel Tubes Under Compressive Load

Abstract

A Vehicle structure is generally built from various materials such as steels and aluminum. In cases oflarge vehicles, such as a bus, square steel tubes are used for main structural components. Generally,a vehicle structure was targeted to absorb more impact energy without increasing too much weight. In order tomeet such requirement, filling foam in the steel tube may be a choice. In this paper, the study on foam-filled inthe square tubes to improve its energy absorption capacity was conducted. The study was carried out with anumber of 25.4x50.8 mm2 and 50.8x50.8 mm2 tubes as experimental specimens. The thickness of tube wasvaried from 1.2, 1.5 and 1.8 mm. The specimen was filled with polyurethane foam. The density of foam wasvaried from 50,100,150,200,250 and 300 kg/m3. The specimens were, then, tested by quasi-static axialcrushing with the universal testing machine. The speed of crushing was 50 mm/min. The experimental resultsrevealed the crush characteristic of steel tubes with various foam densities. It was found that the foam-filledtube can absorb more energy than the empty tube. In the ultimate case, the foam-filled tube with 300 kg/m3can absorb higher energy than the empty tube by 116.04 %