Role of Internal Heat Diffusion on the Nonlinear Dynamic Characteristic Recurrence in SWCNTS Free Thermal Vibration: FPU-Beta Model

2021 ◽  
Author(s):  
Heeyuen Koh ◽  
Shohei Chashi ◽  
Junichiro Shiomi ◽  
Shigeo Maruyama
Keyword(s):  
Dynamic Characteristic ◽  
Nonlinear Dynamic ◽  
Internal Heat ◽  
Heat Diffusion ◽  
Thermal Vibration ◽  
Nonlinear Dynamic Characteristic

scholarly journals Nonlinear dynamic characteristic of the spindle-cutter system

2016 ◽  
Vol 18 (7) ◽  
pp. 4824-4835
Author(s):  
Yidu Zhang ◽  
Xiangsheng Gao ◽  
Min Wang
Keyword(s):  
Dynamic Characteristic ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Characteristic

Construction of a nonlinear dynamic characteristic model of pneumatic artificial rubber muscle manipulator using the magnetorheological (MR) brake

2012 ◽  
Vol 23 (9) ◽  
pp. 1011-1018 ◽  
Author(s):  
Hiroki Tomori ◽  
Yuichiro Midorikawa ◽  
Taro Nakamura
Keyword(s):  
Dynamic Characteristic ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Magnetorheological Fluid ◽  
Early Response ◽  
Air Pressure ◽  
Late Response ◽  
Control Performance ◽  
Characteristic Model ◽  
Nonlinear Dynamic Characteristic

An artificial rubber muscle as an actuator was paid attention in this study because the manipulator was found to be safe to human when it comes in contact with human. However, this actuator vibrates easily with a late response because of the applied air pressure. Then, the magnetorheological brake that uses the magnetorheological fluid with an early response is built into the joint and controls the vibration. In this article, we have grasped the dynamic characteristics of a manipulator by the construction of a model for improvement in the control performance of the magnetorheological brake. Furthermore, the simulation was performed using the model, and efficient braking of the magnetorheological brake was examined.

Testing Research and Analysis on the Dynamic Characteristic of the Models of Tooth Surface Flake

2014 ◽  
Vol 602-605 ◽  
pp. 255-259
Author(s):  
Xiang Dong Mao ◽  
Hui Qun Yuan ◽  
Hua Gang Sun
Keyword(s):  
Dynamic Response ◽  
Dynamic Characteristic ◽  
Nonlinear Dynamic ◽  
Dynamic Models ◽  
Primary Resonance ◽  
Theoretical Models ◽  
Singularity Analysis ◽  
Experimental Device ◽  
Tooth Surface ◽  
Nonlinear Dynamic Characteristic

To inspect and forecast the failure of the gearbox equipment, the dynamic models of tooth surface flake are established. The thesis explores the gearbox nonlinear dynamic characteristic caused by tooth surface flake, and researches the variant joggling stiffness caused by flake failure,analyzes the primary resonance of the flake failure. By the singularity analysis, the fault causes the bifurcation mode of the gear system, which shows effect of the generation and evolution of the fault on the dynamic response of the system. Using the experimental device,the theoretical models are tested and verified.

scholarly journals Heat diffusion-related damping process in a highly precise coarse-grained model for nonlinear motion of SWCNT

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Heeyuen Koh ◽  
Shohei Chiashi ◽  
Junichiro Shiomi ◽  
Shigeo Maruyama
Keyword(s):  
Molecular Dynamics ◽  
Memory Effect ◽  
Nonlinear Dynamic ◽  
Md Simulation ◽  
Internal Heat ◽  
Heat Diffusion ◽  
Coarse Grained ◽  
Good Precision ◽  
Time Step ◽  
Macroscopic Motion

AbstractSecond sound and heat diffusion in single-walled carbon nanotubes (SWCNT) are well-known phenomena which is related to the high thermal conductivity of this material. In this paper, we have shown that the heat diffusion along the tube axis affects the macroscopic motion of SWCNT and adapting this phenomena to coarse-grained (CG) model can improve the precision of the coarse-grained molecular dynamics (CGMD) exceptionally. The nonlinear macroscopic motion of SWCNT in the free thermal vibration condition in adiabatic environment is demonstrated in the most simplified version of CG modeling as maintaining finite temperature and total energy with suggested dissipation process derived from internal heat diffusion. The internal heat diffusion related to the cross correlated momentum from different potential energy functions is considered, and it can reproduce the nonlinear dynamic nature of SWCNTs without external thermostatting in CG model. Memory effect and thermostat with random noise distribution are not included, and the effect of heat diffusion on memory effect is quantified through Mori–Zwanzig formalism. This diffusion shows perfect syncronization of the motion between that of CGMD and MD simulation, which is started with initial conditions from the molecular dynamics (MD) simulation. The heat diffusion related to this process has shown the same dispersive characteristics to second wave in SWCNT. This replication with good precision indicates that the internal heat diffusion process is the essential cause of the nonlinearity of the tube. The nonlinear dynamic characteristics from the various scale of simple beads systems are examined with expanding its time step and node length.

scholarly journals Nonlinear Dynamic Characteristics Analysis of Shift Manipulator for Robot Driver with Multiple Joint Clearance

2021 ◽  
Author(s):  
Gang Chen ◽  
Xinyao Xu
Keyword(s):  
Dynamic Characteristic ◽  
Contact Force ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Force Model ◽  
Characteristic Model ◽  
Clearance Joints ◽  
Clearance Joint ◽  
Nonlinear Dynamic Characteristics ◽  
Nonlinear Dynamic Characteristic

Abstract The clearance joint is very important to the nonlinear dynamic characteristics of mechanism. This paper presents a nonlinear dynamic characteristic model of shift manipulator for robot driver based on multiple revolute clearance joints to improve dynamic characteristics. The relative penetration depth and velocity between pin and bushing are obtained by establishing the kinematic model of the shift manipulator with clearance joint. Based on the improved L-N contact force model and the modified Coulomb friction model, the normal contact force and the tangential contact force of clearance joint are analyzed. With full clearance joints, the nonlinear dynamic characteristic model of the shift manipulator for robot driver is established. The nonlinear dynamic characteristic laws of the shift manipulator including the end displacement, velocity, acceleration and active joint driving torque are analyzed by different sizes of clearance joints. And the performance test of the shift manipulator for robot driver is conducted. The results demonstrate that the nonlinear dynamic characteristics are well analyzed and verified through the presented characteristic model with clearance joints.

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