In this study, the response of the nickel nanowire (NW) subjected to constant strain amplitudes in the range of 0.02–0.12 during cyclic deformation is investigated. The studies are carried out using molecular dynamics (MD) simulations on perfect and defect nickel NW containing ∼ 925,965 atoms. Embedded atom method (EAM) potential is used to model the interactions between nickel atoms. Initially, tensile test is conducted to determine the yield stress and yield strain of the NW at strain rate of 10⁹ s⁻¹ and temperature of 300 K. The yield stress is observed to be 14 GPa and the corresponding strain is 0.17. The cyclic deformation tests are carried out at a temperature of 300 K. During the cyclic deformation at strain amplitudes of 0.02 and 0.04 the plastic deformation features such as slip lines or slip bands do not appear on the surface of the NW's even after 1000 cycles of straining. These features surface when the strain amplitudes are above 0.04 and their density increase with the strain amplitude and cycles. The NWs exhibit asymmetric stress-strain (compression-tension) hysteresis loops at all the strain amplitudes and up to 1000 cycles. The compressive stress is observed to be higher than the tensile stress for all the cycles. The defect nickel NWs have also exhibited similar behavior as that observed in perfect NWs. Further, it is observed that the width of the loops increases with an increase in the strain amplitude and also with the number of cycles due to softening. The NWs did not fracture even after cyclic deformation for 1000 cycles which could be due to the lower strain amplitudes employed in the present study. Cylindrical shape NWs of different sizes are also investigated by subjecting to similar cyclic deformation conditions as above and are found to show similar behavior.

在这项研究中，研究了镍纳米线（NW）在循环变形过程中在0.02-0.12范围内的恒定应变幅度下的响应。使用分子动力学（MD）模拟对含〜925,965个原子的完美和有缺陷的NW镍进行了研究。嵌入原子法（EAM）势用于模拟镍原子之间的相互作用。首先，进行拉伸试验以确定应变速率为10 ⁹ s ^-1的NW的屈服应力和屈服应变温度为300K。屈服应力为14 GPa，相应的应变为0.17。循环变形测试在300 K的温度下进行。在0.02和0.04应变幅度的循环变形过程中，即使经过1000次循环，塑性变形特征（如滑移线或滑移带）也不会出现在NW的表面上。紧张。当应变幅度大于0.04时，这些特征会浮出水面，并且它们的密度会随着应变幅度和周期的增加而增加。NW在所有应变幅度和最多1000次循环中均显示出不对称的应力-应变（压缩-拉伸）滞后回线。在所有循环中，观察到压应力高于拉应力。缺陷镍纳米线还表现出与完美纳米线中观察到的相似的行为。更多，可以看到，环路的宽度随着应变幅度的增加以及由于软化而产生的循环数的增加而增加。即使经过1000次循环变形后，NW也不会断裂，这可能是由于本研究中采用的应变幅度较低所致。通过经受与上述相似的周期性变形条件，还研究了不同尺寸的圆柱状NW，并发现其表现出相似的行为。