In this thesis, the crushing behavior of thin-walled tubes under quasi-static and dynamic loading are investigated. To simulate this behavior the software code ABAQUS/Explicit ver. 6.4 was used and FE models were constructed to study the characteristics of empty and foam-filled tubes. Parametric studies were conducted to determine the effect of different parameters such as the number of oblique sides, the foam density, the tapered angle, the wall thickness and the boundary conditions on crushing behavior of rectangular tubes. The computed characteristic included the deformed shapes, load-displacement, fold length, specific energy absorptions and crush force efficiency. The FE results are then compared with the existing solution as well as the available experimental results which are shown to be in good agreement. Rectangular thin-walled tubes also have been investigated under oblique impact loading. Numerical results show that the tapered tubes are capable of withstanding oblique impact loading as effectively as axial loads and also FE results are in good agreement with test results. The investigation shows that the thin-walled tapered energy absorbers can properly be used in oblique impact loading applications. Generally it was recognized that the foam-filled tapered energy absorbers are the most suitable energy absorbers among others.
