The prediction of compressive properties of foams at large strains and in a wide range of strain rates is still an open issue. In this work we propose a visco-hyperelastic formulation, suitable for large finite strain applications, for the prediction of the compressive response of foams that takes into account the viscoelasticity of the polymer, nonlinear damping, nonlinear behaviour of the cellular structure and effect of gas permeability through the pores at high strain rates. A mathematical expression of the continuous relaxation spectrum is proposed to model the viscoelastic behaviour of the polymer. The relaxation spectrum is then discretized with the desired accuracy required for the subsequent numerical simulations. The model parameters are identified by coupling dynamic measurements at small strain with static ones at large strain. The results are validated by comparing numerical predictions with experimental data from compressive tests up to 50% strain performed at strain rates spanning over 6 degrees of magnitude.

泡沫在大应变和大应变速率范围内的压缩性能的预测仍然是一个未解决的问题。在这项工作中，我们提出了一种适用于大型有限应变应用的粘-超弹性配方，用于预测泡沫的压缩响应，其中考虑了聚合物的粘弹性，非线性阻尼，泡孔结构的非线性行为以及气体的影响高应变率下通过孔的渗透性。提出了连续弛豫谱的数学表达式来模拟聚合物的粘弹性行为。然后，以随后的数值模拟所需的所需精度离散化弛豫谱。通过将小应变下的动态测量与大应变下的静态测量耦合来识别模型参数。