M.Sc. Tezi Görüntüleme

      Thin-walled tubes have a wide range of applications in automotive industry due to their superior energy absorbing capability as well as their lightweight. Recently, there has been a growing interest in filling in the gaps of tube with pressurized air or foam materials. For this reason, the static and dynamic compressional behaviours of pressurized thin-walled tubes were experimentally and numerically investigated. The static experiments were carried out with tubes at different internal pressures. The dynamic experiments were carried out using a gas gun test setup at different projectile velocities for with different internal pressures. Arbitrary Lagrangian Eulerian (ALE) approach was used to model the air in numerical models, which variable pressure effects during tube deformation were therefore taken into consideration. Numerical analysis under axial loading were run to examine the influence of both wall thickness- internal pressure relationship and impact velocity effects for each flat and conical tubes. Also, to investigate the relationship between oblique impact and internal pressure a few numerical analyses were carried out for the flat tubes. From the analyses, the curves of the impact force, absorbed total energy and internal pressure distribution with respect to deformation amount were obtained. In addition, sudden changes in internal pressure and the occurrence of pressure waves at high impact velocities for pressurized tubing have been investigated. It has been observed that the internal pressure changed both the tube deformation the modes and the value of the average impact force. In addition, the amount of absorbed total energy seriously increased.