Calibration of Material Models for the Numerical Simulation of Aluminium Foams – MAT 154 for M-PORE Foams @ 3 Loads

Metallic foams are very promising for engineeristic applications due to their peculiar characteristics, like the high energy-absorbing property coupled with a reduced weight. Even if applications can be widespread in several fields, such as automotive, civil, aerospace, etc., industrial requirements are still far to be fully accomplished, especially in terms of technological processes and a whole mechanical characterization. Material modeling of metallic foams, like the aluminium ones, is a crucial point for performing accurate numerical simulations along with the design phase. Material models available in the explicit, non-linear finite element code LS-DYNA® represent a very efficient way to handle and to investigate foam behavior. An extended experimental/numerical activity has been set out at the aim to calibrate and validate suitable material models with respect to different aluminium foams and several loading conditions. While a previous phase of the activity [1] has been focused on the assessment of a procedure addressed to point out, starting from the available experimental data, the key points of material model calibration, the current activity has been focused on the procedure application, i.e. the exploitation of the built-up methodology in respect of calibration of M-PORE open cells aluminium foam at three different loading conditions. A good number of foams material models are available in the LS-DYNA database, and further in the last years different enhancements have been performed at the goal to include the physical phenomenons able to increase the accuracy of the models. Amongst the available ones, MAT 154 (MAT_DESHPANDE_FLECK_FOAM) has been here chosen because it provides satisfactory results compared with the experimental ones, but at the same time it still requires to be studied for more loading conditions. Since the calibration process requires to optimize the material model free parameters according to different objectives, LS-DYNA has been coupled with modeFRONTIER®, Process Integration and Design Optimization software platform. Once all the FE (Finite Element) models related to the corresponding experimental tests have been integrated into modeFRONTIER, a first sensitivity analysis has been performed at the purpose to get confidence with MAT 154 behavior and then an efficient optimization phase in order to pursue the numerical configurations satisfying the different targets provided by experimental tests. Efficient and intuitive post-processing tools have been applied firstly to get a deep knowledge of the investigated phenomenons and eventually to look for the best solutions.