预应力作用下双层石墨烯低温热振动

发布时间：2018-11-13 07:05

【摘要】：热振动对纳尺度器件动力学特性有着重要的影响.为此,建立了预应力作用下,考虑量子效应的双层矩形石墨烯的等效连续介质模型.计算了不同预应力作用下,不同温度时双层石墨烯的固有频率和均方根振幅.双层石墨烯层间存在范德华相互作用,其同向振动固有频率与相同尺寸单层石墨烯固有频率相等,双层石墨烯存在大于同向振动频率的反向振动频率.考虑量子效应板模型得到的均方根振幅值小于结合能量均分原理板模型得到的结果.且随着温度的降低,两种板模型结果之间的差值增大,量子效应越来越明显.随着预应力的增加,双层石墨烯的固有频率值增加,均方根振幅值降低,量子效应的影响逐渐增加.预应力对同向振动的影响远大于对反向振动的影响.分析了零点能量对双层石墨烯热振动的影响,当计入零点能量后,石墨烯均方根振幅大于结合能量均分原理板模型预测的结果,且在零温时依然存在不为零的振幅.
[Abstract]:Thermal vibration plays an important role in the dynamic characteristics of nanoscale devices. For this reason, an equivalent continuum medium model for bilayer rectangular graphene considering quantum effect is established under the action of prestress. The natural frequencies and root-mean-square amplitudes of bilayer graphene at different temperatures and different prestressing forces were calculated. There is a van der Waals interaction between two layers of graphene. The natural frequency of the codirectional vibration is equal to the natural frequency of the same size of the monolayer graphene, and the reverse vibration frequency of the double layer graphene is larger than that of the same direction vibration frequency. The root-mean-square amplitude obtained by considering the quantum effect plate model is smaller than that obtained by the plate model based on the principle of energy equalization. With the decrease of temperature, the difference between the results of the two plate models increases, and the quantum effect becomes more and more obvious. With the increase of prestress, the natural frequency of bilayer graphene increases, the mean square root amplitude decreases, and the effect of quantum effect increases gradually. The influence of prestress on the codirectional vibration is much greater than that on the reverse vibration. The effect of zero energy on thermal vibration of bilayer graphene is analyzed. When the zero point energy is taken into account, the amplitude of root mean square of graphene is larger than that of the plate model based on the principle of energy equalization, and the amplitude is not zero at zero temperature.
【作者单位】：南京航空航天大学机械结构力学及控制国家重点实验室;
【基金】：国家自然科学基金优秀青年科学基金(11522217) 江苏省333高层次人才培养工程项目南京航空航天大学博士学位论文创新与创优基金(BCXJ13-03) 中央高校基本科研业务费专项资金资助
【分类号】：TQ127.11

【参考文献】