Application of Molecular Dynamics Simulation in the Study of Damage and Repair Mechanism of Cable Insulation Sheath Materials
During the laying and use of cable insulating sheaths,they are inevitably affected by mechanical or thermal stress,which can cause microcrack damage.If not repaired in a timely manner,the damage can easily lead to a rapid decline in their mechanical and insulation properties,material performance failure,and even circuit faults.This paper reveals the mechanism of damage to cable insulation sheath materials based on molecular dynamics theory.Through molecular dynamics simulation calculations,the changes in the free volume and cohesive energy of the sheath material under damage are obtained.The influence of damage on the insulation performance of the material and the mechanism of microcracks are also analyzed from the perspective of molecular dynamics theory.Due to the lack of self-healing properties in conventional polyethylene and other cable sheath materials,cracks are difficult to repair in a timely manner,resulting in a gradual loss of performance.Therefore,the development of cable sheath self-healing materials introduces reversible host guest self-healing functional groups that dissociate and bind into the material.When the material is damaged,the purpose of repair is achieved through the recombination of functional groups.The results of simulating the new material using molecular dynamics show that after self-healing,the free volume of the material decreases,the cohesive energy density increases by 23％,and the solubility parameter increases by 10.9％,demonstrating the effectiveness of self-healing.
万方数据
维普
