Establishment Of A Damage Evolution Model For Particle Reinforced Aluminum Matrix Composite And Numerical Simulation Of Power Spinning

Particle reinforced aluminum matrix composite has excellent comprehensive performance such as high specific strength, high specific stiffness, high wearability, high dimensional stability, low density and low heat expansion coefficient. It has a good application prospect in advanced weapons and aerospace technology field. The advantage of power spinning is saving material, flexible and available to form large diameter tube. Power spinning is a kind of effective processing method for composite tube. Because of the existing of reinforced particle, the continuity of matrix is destroyed and plasticity decreases during power spinning processing for particle reinforced aluminum matrix composite. Micro cracks are produced inevitably inside forming parts to be called damage. When micro cracks are growing and converging, they will eventually cause the macro fracture of composite. This paper adopted the method of combination of establishing damage evolution model and numerical simulation for composite. Macro fracture of composite during high temperature deformation and change law of damage value in power spinning were predicted. Theoretical basis was provided for actual production process and optimization.This paper carried on the thermal simulation experiment for particle reinforced aluminum matrix composite. The stress-strain curves were obtained, the high temperature constitutive equation was established and the parameters of the constitutive equation were calculated. The constitutive equation was compared with the experiment and the error value of the equation was 3.8%. The result showed it could better predict the high temperature flow behavior for composite.The high temperature deformation damage evolution model was established based on the theory of continuum damage mechanics considering the influences of deformation temperature and strain rate. The damage evolution curves were obtained in different deformation conditions by high temperature multi-step tensile test referring to elastic modulus methed that Lemaitre proposed. Parameter of model was determined by damage evolution curves data fitting A(Z)= 2.22769-0.09438In Z+0.00238In2 Z.The judgment of macro fracture of composite was determined by damage critical value fitting DC(Z)=0.50915-0.00577 In Z. The model was verified by high temperature compresssion test and the result showed it could achieve better results for macro fracture of composite.The finite element model of power spinning for particle reinforced aluminium matrix composite was established based on simulation software. The damage evolution model was coupled and damage parameters were imported into software. The changing law of the stress and strain, three dimensional stress in spinning roller contact zone, liquidity of material and the distribution of damage value were analyzed by numerical simulation. The influences of different temperature, thinning rate and feed ratio on the equivalent stress and damage value were discussed. The results showed that damage value decreased with the rise of temperature, increased with the increase of thinning rate and increased with the increase of feed ratio.3D surface of damage value were drawn. The safety of material processing parameters could be choosed by 3D surface to avoid material macro fractuer. The prediction of numerical simulation was validted by physical experiment and the result was better consistent.