Developing an adaptive FE model to reflect the effective mechanical properties in porous elastomeric materials

Simulation of the microstructure of materials is not usually an efficient approach to estimate the mechanical response in the macro-scale porous components. This paper establishes an adaptive numerical model which reflects the effective mechanical properties of the elastomeric foam materials in the macro-scale, based on the material response in local points. The proposed adaptive model is capable of characterizing the dominant state of stress at each section point and assigning the corresponding mechanical properties from a developed material library. This material library can propose different stress-strain responses of the foam material based on mechanical characterization experiments and using the best-fit energy functions. The material of study is an elastomeric foam with a blend of Polyethylene/Ethylene-vinyl acetate (PE-EVA). The efficiency and performance of the adaptive model were examined using two practical case studies, in which the material was exposed to multiaxial stress conditions (a foam beam and a composite sandwich beam with a foam core under a concentrated loading). The adaptive model accurately predicts the dominant response of the foam beam and composite sandwich beam under flexural loading conditions. However, the uniaxial hyperelastic material models, calibrated by the pure tensile or compressive response of the foam material, dramatically overestimate or underestimate the experimental results.