Based On The Cell Body Model Of Particle Reinforced Composites Coupled Field Numerical Simulation

Particle reinforced metal matrix composites (PRMMC) is gained high attention for its high specific strength, high specific rigidity, high temperature and corrosion resistance. In the thermo-electro-structural coupled field, composite materials will be partly destroyed, because of the asymmetrical temperature and stress field aroused by the particles. Thus, it is significant and valuable to study on the mechanical properties and meso-damage mechanism of particle reinforced metal matrix composites in a multi-field.In this paper, based on the ANSYS finite element analysis platform, the following research work is carried out:1. The multi-pellet random distribution unit cell model is improved and used to calculate the modulus of PRMMC in this paper. The computational results by this method are in accordance with those of reference.2. The stress field of PMMC with different volume fraction is calculated in this paper. And the influence of different volume fraction and different spatial distribution on the stress field is analyzed. The derivation and evolution mechanism of the cracking, debonding, micro-crack initiation and meso-damage of PRMMC is analyzed, compared with the results of the micromechanics experiment.3. The current field, temperature field and stress field of PRMMC with different volume fraction and different particle shape are calculated using plane symmetry cell model, one particle sphere unit cell model, multi-pellet random distribution unit cell model. The influence of volume fraction, particle shape and distance on the distribution of current, temperature and stress is analyzed. By analyzing to Joule heat stress field, the derivation and evolution mechanism of the meso-damage of PRMMC in multi-field is analyzedBased on these studies, the following conclusions can be obtained:1. By comparing the literature's experiment results with the simulation results of the elastic modulus of the composites, the multi-pellet random distribution unit cell model's rationality is confirmed. By comparing the results of the digital holographic interferometry with the simulation results of the deformation of the composites, the plane symmetry cell model's rationality is confirmed.2. From the stress field of PRMMC in tension load, it can be concluded that the interference between particles is related with not only the distance between particles, but also the positions of them. When the angle between the line of two particles and loads is smaller, the interference is serious. And when the angle is larger than 45°, the interference is weak. In composite materials, the micro-cracks initiated and expanded from the high-stress zone in particles lead to the fracture of particles, and the micro-cracks initiated and expanded from the interface in matrix lead to the debonding of interface.3. From the computation results of PRMMC with different models and different volume fraction in the thermo-electro-structural coupled field, we can concluded:Ⅰ. The resistance, the Joule heat and temperature of the composites increase as the increasing of the volume fraction.Ⅱ. Compared different spheroidal particle model, the results show that the maximum temperature increases as the curvature radius of particles perpendicular to the current decreases.Ⅲ. The influence of the distance between particles on maximum Joule heat is serious. When the distance is equal to the radius of particle, the Joule heat is largest. When the distance is larger or smaller than the radius, the Joule heat will decrease.Ⅳ. The Joule heat stress is concentrated in the interface of particles, and the interface is weakest in PRMMC. In the thermo-electro-structural coupled field, the micro-crack initiates and expands from the interface, and the disbonding of interface is the main damage of PRMMC.