Research On Mechanical Behavior And Properties Of Rubber Polymer Composites

Aviation tires are serviced under high-speed and the high-load conditions,carrying the take-off and landing task of the aircraft,and play a vital role in the safety and stability of the trunk passenger aircraft and the ground handling of the military fighter.Therefore,research on high-performance aviation tire has always been a hot spot in the international research.Optimizing rubber compound formulas and improving the mechanical properties of them are key factors to enhance the working performance and extend the service life of the tire.It is difficult to investigate the influence of unilateral factors on the mechanical properties of rubber composites by experiments.The mechanical constants of the new materials need to be obtained first in the finite element analysis,so it is impossible to design and study the new rubber composites according to the needs through FEA.Molecular dynamics simulation starting from the interaction potentials between atoms establishes the atomic structure model of new materials to compute the properties of them.In this dissertation,Poly-isoprene molecular chain model with different polymerization degrees and carbon nanotube(CNT)model are established by Materials Studio respectively,and the following calculations and analysis are conducted:(1)According to the number of atoms contained in the molecular chains with different polymerization degree,five amorphous box models loaded with different number of molecular chains are established(the total number of atoms should be over 10000),and the density and elastic mechanical parameters of these models are acquired through energy minimization and molecular dynamics simulation.Based on the calculation results,the most suitable polymerization degree for simulating the properties of poly-isoprene is determined.(2)Based on the selected degree of polymerization,a model with about 5000 atoms is established,and the mechanical properties of the poly-isoprene rubber(IR)matrix at different temperatures are calculated.The glass transition temperature of the IR matrix is obtained from the variation of density and mechanical parameters with temperature.(3)A CNT/IR composite model is established by importing CNT into the model,and then the physical and mechanical properties of the composite model is calculated at different temperatures.The calculation results show that the addition of CNT increases the density of the material,the glass transition temperature of the material,and significantly enhances the stiffness and strength mechanical propertiesof the material.The simulation results show that the mechanical properties of the material is improved because the CNT strengthens the interaction between the atoms of the material.