Modeling the behavior of thin-walled tubes with different fillers at the maximum load in solving the problems of crashworthiness

Abstract

The article considers issues related to the choice of effective finite-element modeling thin-walled tubes with different types of fillers (imitating elements of car bodies and cabs of frame-type cars) with quasi-static bending load, causing the tube and filler to collapse, in the context of optimal design. Thin-walled pipes made of aluminum alloy AMg6 with aluminum foam fillers; epoxy resin and composite (consisting of Poraver balls and epoxy resin) were the subject of the study. Aluminum foam is an elastoplastic material; it is one of the best fillers for solving the problems of crashworthiness, although it requires expensive technological equipment for filling. Epoxy resin is a fragile material, but inexpensive, affordable and technologically “convenient”. In addition to the influence of the filler on the tube mechanical properties the effects of the constrained behavior of the filler material under the ultimate bending loading of the tube are investigated. To verify the theoretical assumptions, tests were performed on the Zwick Z100 universal testing machine (for a hollow thin-walled tube made of aluminum alloy and similar tubes with fillers). Here there are the results of numerical computations and the results of the experiment (the error of calculations does not exceed 8 %). The most rational material in terms of energy-mass ratio is aluminum foam (with an increase in sample mass of 2.1 times the mechanical properties increased tenfold). Other fillers give much worse results for the same parameters. Using the proposed finite element models (FEM), allows assessment of the effectiveness of existing and being created filler materials for refining the car bodies and cabs according to the requirements of crashworthiness