Molecular Dynamics Simulation Of Friction Properties Of Nature Rubber And Carbon Material

Three models were displaced in this article.First,the friction between NR and diamond sole plate were preformed to reveal the heat generation process of the material;Then the pullout process of CNT was designed to reflect the matrix temperature response and the pullout force of CNT;Finally,the friction process of NR/CNT composite material was carried out.During this process,friction and pullout process were presented together and comprehensively revealed the thermal properties and some mechanical properties of the composite material.The core idea was that whether the pullout process or friction process,the matrix was layered to study the relationship between the whole and the part,so as to provide a reference for the performance evaluation of the composite material.For the first part,we established a friction model to explores the overall temperature change trend of the substrate,and to further understanding the friction heat generation.Besides we examined the temperature rise of the layered substrate under different friction speeds,it showed that the matrix temperature was higher when the friction speed was slower and lower when faster.Different roughness had different effects on substrate heating.The smooth bottom plate only had Van der Waals force on the substrate,and when the bottom plate was rough,in addition to the Van der Waals' drawing effects,the rough peaks would penetrate into the substrate and affect the matrix molecular chain and this process increases matrix heat production.By investigating the coordinates of the center of mass displacement to understand the posture during friction.Finally,the potential energy change diagram of the friction process was analyzed to reveal how the molecular potential changed.In the second part,a NR/CNT matrix was first established,and the drawing process were performed at different ambient temperatures.The results showed that the temperature curve of the whole matrix increases linearly,and the higher thetemperature,the greater the growth rate.As for the stratified matrix,we obtained that the slip layer caused by drawing expands outward when the ambient temperature increases.By changing the drawing speed,the "sensitivity" of the temperature response of each layer was discussed,and we will have more intuitive understanding of the matrix slip by analyzing the path file and the different heating points of the stratified matrix.Finally,we recorded the relationship between the ambient temperature and the CNT stress during the drawing process.it showed that at the same speed,the higher the temperature,the greater the pulling force;at the same temperature,the higher the speed,the greater the pulling force.The third part of the friction pair was the NR/CNT composite matrix and the rough diamond base plate.During the friction process,the internal CNT were forced to be pulled out of the matrix and finally fall off.First,the interface binding energy between CNT and NR and the atomic distribution of the friction process were discussed.we found that the higher the ambient temperature,the greater the interface binding energy.Second we discussed how to calculate the extraction energy and the interface shear stress.it showed that the extraction energy decreases with increasing temperature and the interface shear stress increases.Third we calculated the temperature distribution of the whole matrix and the layer matrix during the friction process.The rubber matrix added with CNT can converge the whole matrix temperature to a fixed value.Finally,in exploring the CNT forces,we found that the CNT axial forces increase when increasing the ambient temperature.Due to a good balance on center of mass displacement curve,we see a better hardness in composite matrix.The micro experiments cost a lot,but molecular dynamics will make it cost efficiency.We focus on the friction process of NR / CNT composite materials.The existing literature mostly disturbs the composite matrix with a probe,but the probe scribing the matrix by only a single rough peak,and cannot represent the common effect of many rough peaks.Here we consider multiple rough peaks,the movement of the friction pair is also closer to the actual friction.