Modeling, characterization and parametric identification of low velocity impact behavior of time-dependent hyper-viscoelastic sandwich panels

Accurate and deep understanding of the mechanical and physical behavior of sandwich panels with soft elastomeric foams, e.g. cellular solids, such as ethylene vinyl acetate is a key task in designing these structures, and also optimizing their mechanical behavior. The main objective of the present research is to present an applicable method to determine the non-linear hyper-viscoelastic response of elastomeric sandwich panels to low velocity impact loadings, by presenting an applied method. A combination of experimental results and finite element analysis, in conjunction with optimization method is used to determine the hyper-viscoelastic behavior of the studied sandwich panels. The suggested combinational approach can replace the time-consuming and expensive creep and/or relaxation experiments. A relatively simple approach is proposed to identify time-dependent viscoelastic material behavior of elastomeric foams. The calibrated finite element model is utilized to perform a set of parametric studies and the effect of various material properties is studied on the low velocity impact response of sandwich plates.

Polymeric foams with functional nanocomposite cells

Elastomeric foams with controlled cell size and composition are formed by using calcium alginate hydrogel beads as templates.

Large Deformations of Low Density Open-Cell Elastomeric Foams: Kelvin Model Study

Based on Kelvin model, the large deformations of elastomeric foams were simulated by finite element method (FEM). Numerical results indicated that edge bending, edge stretching and edge torsion were important deformation mechanisms of low density open-cell Kelvin foam. The hyperelasticity of the cell material had little effect on the macro-mechanical properties of the foam at low strain in [111] direction and finite compressive strain in [100] direction when edge bending was the main deformation mechanism of the foams. With the increase of the uniaxial tensile strain, edge stretching played notable roles, which resulted in that the hyperelasticity of the solid had significantly influence on the deformation of the foam at large uniaxial tensile strain. And the high strain compressive stress-strain curves in the [111] direction based on the hyperelastic relation differed from the linear elastic results remarkably as edge torsion was an important deformation mechanism of the foam.