Application Of Meso-damage Mechanics In Statistical Simulation Of Composite Characteristics

As composites are widely used in engineering, statistically simulating the engineering properties of composites and predicting the strength and properties of composites is becoming a promising research interest. The following work has been done based on this research background.The basic contents of meso-damage mechanics were presented and several basic theory models for application of meso-damage mechanics were proposed in the paper. The stress performance and damage failure mechanism of several composites were numerically simulated according to statistical simulation method, and results of reference significance were obtained. The damage process of unidirectional metal matrix composites, the fracture process of polymer matrix composites and concrete composites, and the stress performance and meso-failure process of ultrananocrystalline film composites were studied in terms of molecular dynamics, meso-damage mechanics and dynamic Monte Carlo method. Corresponding relation and figures regarding failure process were given. This micro-macro statistical simulation method has some reference significance in further studying mechanical properties of composites using meso-damage mechanics in application.Based on meso-damage mechanics theory models and Monte Carlo statistical simulation method, the evolution properties of deformation, damage and destruction of composite micro-meso structures were statistically simulated. The following conclusions were obtained.(1) The strength of unidirectional fiber reinforced metal matrix composite depends on situ strength of fiber other than the strength of original fiber. The degradation of situ fiber results in low stress failure of composites.(2) For polymers containing second-phase particles matrix, the increase of volume fraction of particles causes decrease of macro-yield stress. The maximum normal stress increases with increasing dimensional variations between particles, and increases also with decreasing the volume fraction of particles.(3) For ultrananocrystalline films with monocrystal diamond structure, the tensile strength of the diamond block decreases with increasing the specimen size. However, it appears that the size effect on the strength of diamond is more significant at lower loading rate as compared with that at higher rate. The simulated tensile strength obtained from the smallest specimen under the lowest strain rate represents the ultimate strength.