Polylactic acid (PLA) is one of the highly applicable bio-polymers in a wide variety of applications including medical fields and packaging. In order to quantitatively model the mechanical behavior of PLA and PLA based bio-composite materials, and also tailor new bio-composites, it is required to characterize the mechanical behavior of PLA. In this study, thin films of PLA are fabricated via hot-pressing, and tensile experiments are performed under different strain rates. To model the mechanical behavior, an elasto-viscoplastic constitutive model, developed in a finite strain setting, is adopted and calibrated. Using the physically-based constitutive model, all regimes of deformation under uniaxial stress state, including post-yield softening, were adequately captured in the simulations. Also, the rate dependency of the stress–strain behavior was properly modelled.

聚乳酸 (PLA) 是一种高度适用的生物聚合物，其应用范围很广，包括医疗领域和包装。为了定量模拟 PLA 和 PLA 基生物复合材料的力学行为，并定制新的生物复合材料，需要表征 PLA 的力学行为。在这项研究中，PLA 薄膜是通过热压制造的，并在不同的应变速率下进行拉伸实验。为了模拟机械行为，采用并校准了在有限应变设置中开发的弹粘塑性本构模型。使用基于物理的本构模型，在模拟中充分捕获了单轴应力状态下的所有变形机制，包括屈服后软化。还，