Research On Compression And Resilience Performance Of Carbon Nanotubes Based On Molecular Dynamics Simulation

Carbon nanotubes(CNTs)have many excellent properties and are widely used in composite materials.At present,the main method of studying nanoscale CNTs is the molecular dynamics method.This method obtains the mechanical properties of CNTs by simulating the movement of atoms.This paper mainly uses Lammps software to simulate CNTs.The main content includes the following aspects:(1)Simulating the mechanical behavior of(6,6)-28 cell single-walled CNTs under compressive load,it is found that the critical buckling strain is 7.48%,and the energy release point is 7.79%,indicating that the release of energy is delayed during compression When the compressive strain reaches 12%,more and more concave regions of the CNTs are generated until the structure is destroyed.(2)The effects of temperature and loading speed on the compression properties of(6,6)-28 CNTs are studied.The mechanical behavior of carbon nanotubes at different temperatures is analyzed,it is found that the temperature increase will increase the critical strain point of CNTs,and the elastic modulus of CNTs is less affected by temperature;it is analyzed that under different loading speeds,CNTs changes in the critical buckling strain point and energy release point of nanotubes,and increasing speed will make the critical buckling strain point larger.In the case of variable speed,the main research is to change the loading speed of CNTs at different strain stages,and the stress and strain will change differently.(3)Study the resilience performance of(6,6)-28 single-walled CNTs under different compressive strains.It is found that the stress is unloaded before the energy release point of 7.79%.Since its energy is not lost under this strain,its energy It can always rebound to its original length;As the strain increases,its rebound rate becomes smaller and smaller.When the compressive strain is before 14%,it has a rebound rate of 90% and retains some elasticity.When the compressive strain exceeds 30%,the concave part is completely destroyed and loses its resilience.(4)The CNTs with a compressive strain of 10% are compressed under different conditions,and it is found that the resilience of CNTs decreases with the increase in diameter,and gradually decreases with the increase in length.For CNTs with the same aspect ratio nanotubes,when the diameter is less than 1.153 nm,the diameter has a greater impact on its resilience performance,as the diameter increases,the resilience performance gradually decreases;when the diameter is greater than 1.153 nm,the resilience performance is almost the same;research the resilience of(6,6)-28 single-walled CNTs increases with the increase of loading speed and increases with the increase of temperature.When the loading speed is greater than 1.12x10-3nm·step-1,it has 100% resilience performance,when the temperature is less than 1000 K,its resilience performance increases with the increase of temperature,when the temperature is greater than 1000 K,its resilience performance gradually tend to a certain value.