Experimental reseraches and numerical simulations of combined collision energy absorber

Abstract

The subject of this paper is experimental researches and numerical simulations of combined collision energy absorber. The mentioned elements are parts of passive safety measures of railway vehicles. This type of absorbers works on the principle of deformation using shrinking and folding process of the tubes. The idea was to use process of shrinking and folding of the tubes in a parallel mode to absorb as much of the collision kinetic energy as possible by controlled deformation, with limited dimensions of absorber. Energy absorption occurred by elastic-plastic deformations of the tubes and friction between the tube and the cone bush. Using combined method, during the collision, energy absorption starts in the tube which is compressed into cone bush. After pre-defined stroke in the process of energy absorption the simultaneous process of folding of the outer tube starts, so both tubes deform in parallel mode during the rest of the stroke. In this way the force gradually increases without undesirable peaks during the entire stroke, resulting significant bigger amount of absorbed energy. Experimental investigations of combined absorber were realized in laboratory conditions. During experimental investigations the stroke and force were measured. The numerical simulations were used for checking the absorption power of absorption elements before the experimental researches. After the tests were completed, the recorded data were analyzed and force versus stroke diagrams of numerical simulation and quasi-static test were made. Results of calculation using FEM and results obtained experimentaly are in good correlation.