Study On Axial Compression Vibration Characteristics Of Single Walled Carbon Nanotubes

Carbon nanostructures are considered to be materials with great potential in nanotechnology.It has some special electrical,mechanical,optical and thermal properties and can be used to make composite materials with excellent properties.Carbon nanotubes have many extraordinary properties,such as small size,high strength,and high sensitivity.These characteristics make it a core component of bioelectronics,biomedicine,and biosensors.Sensors made of carbon nanotubes mainly use their vibration characteristics for detection.Therefore,comprehensive consideration of the impact of the real situation on the performance of the sensor and the study of its vibration mechanical behavior will help the optimal design and application expansion of the device.CNTs have been widely used in various micro nano electromechanical devices due to their excellent vibration properties.However,it is difficult to guarantee the ideal topological structure of CNTs by existing preparation technologies.There are various defects in CNTs prepared by different preparation methods,such as vacancy,hybridization,doping and stone Wales(S-W)defects.In this paper,the axial vibration properties of single-walled carbon nanotubes(SWCNTs)with or without defects and those with nanoparticles were studied by nonlocal theory and molecular dynamics method.The specific research contents and results are as follows:(1)The LAMMPS software was used to simulate the carbon nanotubes with S-W defects by molecular dynamics.Based on the results of static buckling performance,the dynamic buckling vibration performance of carbon nanotubes with S-W defects was analyzed by non-local elastic theory.Molecular dynamics simulations are used to verify the correctness of the theory and determine the effective range of non-local parameters.The results show that the existence of S-W defects will indeed reduce the vibration characteristics of carbon nanotubes.In addition,the number of defects will aggravate the influence of diameter and chirality angle on its natural frequency and amplitude.(2)The effects of aspect ratio,vacancy defects and S-W defects on the axial compression vibration performance of carbon nanotubes were studied by molecular dynamics simulation.First,a model of carbon nanotubes with or without defects was constructed using MATERIALS-STUDIO(MS).Then,use LAMMPS software to perform molecular dynamics simulation on the defective carbon nanotubes.The effects of aspect ratio,vacancy defects,and S-W defects on the axial displacement of the two types of carbon nanotubes are discussed.The results show that the increase in the aspect ratio makes the maximum axial displacement of carbon nanotubes larger;defects will affect the performance of carbon nanotubes’ axial vibration,and SW defects have greater influence on the axial vibration of carbon nanotubes than vacancies defect.(3)The effects of aspect ratio,vacancy defects and S-W defects on the axial compression vibration performance of carbon nanotubes were studied by molecular dynamics simulation.First,a model of carbon nanotubes with or without defects was constructed using MATERIALS-STUDIO(MS).Then,use LAMMPS software to perform molecular dynamics simulation on the defective carbon nanotubes.The effects of aspect ratio,vacancy defects,and S-W defects on the axial displacement of the two types of carbon nanotubes are discussed.The results show that the increase in the aspect ratio makes the maximum axial displacement of carbon nanotubes larger;defects will affect the performance of carbon nanotubes’ axial vibration,and SW defects have greater influence on the axial vibration of carbon nanotubes than vacancies defect.