The prediction of failure processes in polymer nanocomposites requires accurately capturing different factors such as damage mechanisms, and temperature- and rate-dependent material characteristics. This work presents the development of a finite deformation phase-field fracture model to analyze the thermo-viscoelastic behavior of boehmite nanoparticle/epoxy nanocomposites. To characterize the rate-dependent fracture evolution, the free energy is additively decomposed into an equilibrium, a non-equilibrium, and a volumetric part with a varying definition under tensile and compressive deformation. Furthermore, the Guth–Gold and modified Kitagawa models are adopted to consider the effect of the nanoparticle contents and temperature on the nanocomposites’ fracture behavior. The applicability of the proposed model is evaluated by comparing the numerical results of compact-tension tests with experimental data. The experimental–numerical validation justifies the predictive capability of the model. Numerical simulations are also performed to study the effect of temperature and deformation rate on the force–displacement response of boehmite nanoparticle/epoxy samples in the compact-tension tests.

预测聚合物纳米复合材料的破坏过程需要准确地捕获不同的因素，例如破坏机理以及与温度和速率有关的材料特性。这项工作提出了有限变形相场断裂模型的发展，以分析勃姆石纳米颗粒/环氧树脂纳米复合材料的热粘弹性行为。为了表征与速率相关的裂缝演化，在拉伸和压缩变形下，自由能被累加分解为一个平衡，一个非平衡以及一个具有不同定义的体积部分。此外，采用了Guth–Gold和改良的Kitagawa模型来考虑纳米颗粒含量和温度对纳米复合材料断裂行为的影响。。通过将密实张力试验的数值结果与实验数据进行比较，评估了所提出模型的适用性。实验数字验证证明了模型的预测能力。还进行了数值模拟，以研究压紧试验中温度和变形速率对勃姆石纳米颗粒/环氧树脂样品的力-位移响应的影响。