传输高速纳米流的石墨烯增强复合纳米管的接触动力响应:尺寸依赖性对局部/全局瞬态响应的影响  

Contact dynamics of graphene reinforced composite nanotubes conveying high-speed nanofluid:size-dependence and local/global transient response

作　　者：金其多 任毅如 Qiduo Jin;Yiru Ren(College of Mechanical and Vehicle Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]College of Mechanical and Vehicle Engineering,Hunan University,Changsha 410082,China

出　　处：《Acta Mechanica Sinica》2023年第3期26-41,共16页力学学报（英文版）

基　　金：The work was supported by the National Natural Science Foundation of China(Grant No.52172356);Hunan Provincial Innovation Foundation for Postgraduate(Grant No.CX20210384).

摘　　要：流体输送纳米管在纳米机电系统中起着关键作用.本文研究了输送高速纳米流体石墨烯增强复合材料(GRC)纳米管在横向低速冲击下的接触动态响应和应力场,建立了考虑滑移流、非局部应力和应变梯度效应的尺寸相关模型.基于精细梁理论,推导了流致后屈曲和接触振动的控制方程,其中后屈曲平衡路径为冲击振动分析提供了初始构型.采用两步摄动-高阶Galerkin截断-Runge-Kutta(R-K)方法的计算模式研究接触动力响应.通过收敛性分析,得到了保证精度所需的截断项.获得了接触力曲线、跨中位移时程曲线和应力场,以指导强度设计.此外,还揭示了流致后屈曲纳米管在冲击作用下的动态跳跃失稳行为.结果揭示了非局部应力和应变梯度对接触动态响应和应力场的双重影响,并提供了对尺寸效应敏感的流速范围.Fluid-conveying nanotubes play key roles in nano electromechanical systems(NEMSs).The contact dynamic response and stress field of the fluid-conveying graphene reinforced composite(GRC)nanotube transporting high-speed nanoflow under lateral low-velocity impact are studied.The size-dependent models incorporating slip flow,nonlocal stress and strain gradient effect are established.The governing equations of flow-inducing post-buckling and contact vibration are derived based on a refined beam theory,in which the post-buckling equilibrium provides the initial configuration for the impact vibration analysis.A computation mode of two-step perturbation-higher-order Galerkin truncation-Runge-Kutta(R-K)method is employed to study the contact dynamic responses.Through the convergence analysis,the truncation terms required to ensure the accuracy are obtained.The contact force curves and the midspan displacement time history curves and the stress field are acquired to guide the strength design.Also,the dynamic snap-through instability behaviors of the nanotube under the flow-inducing post-buckling state are revealed.Results reveal the dual influences of nonlocal stress and strain gradient on the contact dynamic response and stress field and provide the flow velocity range sensitive to the size effect.

关 键 词：Slip flow Nonlocal strain gradient theory Fluid-conveying nanotube Low-velocity impact Stress field 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TQ127.11[化学工程—无机化工]