This work addresses the large strain behaviors of thermoplastic polyurethanes (TPUs) spanning a range of fractions of hard and soft contents in both experiment and theoretical modeling. The key mechanical features involve a combination of elasticity and inelasticity, and are quantified experimentally under a broad variety of loading scenarios. A finite deformation constitutive model is then presented to capture the main features of the stress-strain data, which are strongly dependent on fractions of hard and soft contents. The stress-strain behavior of these TPUs is characterized by highly nonlinear rate-dependent hyperelastic-viscoplasticity, in which substantial energy dissipation is accompanied by shape recovery as well as softening. Agreement between the model and the experimental data for the representative TPUs provides physical insight into the underlying deformation mechanisms in this important class of soft materials that exhibit both elastomeric and plastomeric characteristics.

这项工作解决了热塑性聚氨酯（TPU）的大应变行为，该行为在实验和理论建模中都涵盖了一系列硬质和软质成分。关键的机械特征涉及弹性和非弹性的组合，并且在各种载荷情况下通过实验进行了量化。然后提出了有限变形本构模型，以捕获应力-应变数据的主要特征，这些特征主要取决于硬质和软质含量的分数。这些TPU的应力-应变行为的特征是高度非线性的速率依赖型超弹性-粘塑性，其中大量的能量耗散伴随着形状恢复以及软化。