Analytical and numerical investigation of cylindrical energy absorbers with functionally graded thickness

In this study, the crashworthiness of cylindrical tubes with variable thickness, under axial load, is investigated. The loading is applied quasi static. Wall-Thickness changes are considered to follow the nonlinear power distribution equatiion. Firstly, by considering the elastic-perfectly plastic behavior for material, an analytical relition is extracted based on Alexander's theory. Then, in order to increase the accuracy of the results, the effects of work hardening is applied to material behavior and the formulas are rewritten. Finally, to validate the analytical results, using simulation in ABAQUS FE software, several models have been studied in different modes and the results have been compared. The results show an acceptable agreement between the analytical results and the simulation. The final result of this research is presenting two analutical relition beteen absorbed energy and mean force with mechanical properties and geometic parameters of anergy absorber. Moreover, by simplifying the drived analytical equation, we can obtain the basic equations in later researches.