Uniaxial tensile tests were performed to investigate the mechanical properties of the ultra-high molecular weight polyethylene (UHMWPE) with different modification conditions. It was found that the different modification conditions have great influence on the mechanical properties of the UHMWPE. Subsequently, the uniaxial ratcheting behaviors of the UHMWPE/CNF and UHMWPE/HA composite materials were observed under the stress-controlled cyclic tensile condition at room temperature. The dependence of uniaxial ratcheting of composite materials on the mean stress, stress amplitude, stress rate and nano-material content was investigated. The results show that the ratcheting strain and its rate of the two composite materials increase as the mean stress and stress amplitude increase, however, the ratcheting strain and its rate decrease with the increase of the stress rate and nano-material content. Furthermore, it is found that the ratcheting strain of the UHMWPE/HA composite material is more remarkable than that of the UHMWPE/CNF composite material. A new viscoplastic constitutive model is proposed to describe the ratcheting behavior of the UHMWPE composite materials. In this model, a new viscosity function and modified kinematic hardening law were employed. Comparison of simulation and experimental results shows that the simulations are in good agreement with the experimental results.

进行单轴拉伸试验以研究具有不同改性条件的超高分子量聚乙烯（UHMWPE）的机械性能。发现不同的改性条件对UHMWPE的机械性能有很大的影响。随后，在室温下应力控制的循环拉伸条件下，观察到了UHMWPE / CNF和UHMWPE / HA复合材料的单轴棘轮行为。研究了复合材料单轴棘轮对平均应力，应力振幅，应力速率和纳米材料含量的依赖性。结果表明，两种复合材料的棘轮应变及其比率随着平均应力和应力幅值的增加而增加，但是，棘轮应变及其速率随应力率和纳米材料含量的增加而降低。此外，发现UHMWPE / HA复合材料的棘轮应变比UHMWPE / CNF复合材料的棘轮应变更显着。提出了一种新的粘塑性本构模型来描述UHMWPE复合材料的棘轮行为。在该模型中，采用了新的粘度函数和改进的运动硬化规律。仿真与实验结果比较表明，仿真结果与实验结果吻合较好。提出了一种新的粘塑性本构模型来描述UHMWPE复合材料的棘轮行为。在该模型中，采用了新的粘度函数和改进的运动硬化规律。仿真与实验结果比较表明，仿真结果与实验结果吻合较好。提出了一种新的粘塑性本构模型来描述UHMWPE复合材料的棘轮行为。在该模型中，采用了新的粘度函数和改进的运动硬化规律。仿真与实验结果比较表明，仿真结果与实验结果吻合较好。