Numerical evaluation of friction effects on the energy absorption of square profiles under bending load

Abstract

Friction is often associated with undesirable effects on mechanical systems. However, friction could be useful to increase the energy absorption capacity of thin-walled structures subjected to bending loads. The current article proposes the use of friction as an additional energy dissipating mechanism to plastic deformation. For this purpose, three different friction fixtures are presented and numerically evaluated using Abaqus/Explicit software. The friction fixtures were placed at the ends of square profiles generating internal, external and combined friction. In all cases, the square profiles were made of aluminium 6063-T5. The reliability of the numerical results was experimentally validated by a modified three-point bending test with friction. The numerical results for the three arrangements were compared with the results obtained for a profile without friction. According to our results, in all cases friction improves the energy absorption performance of the square profiles in a range from 48.71% to 179.19%. Finally, the best crashworthiness performance was obtained when external friction is generated at the ends of the tube. An increase in the crush force efficiency (CFE) parameter up to 71.47% respect to a typical profile was computed. Thus, the effectiveness of the friction mechanism was demonstrated.