Abstract: Based on the single particle representative volume element of particle reinforced composites , the mono-
tonic tensile st ress-strain curve and uniaxial ratcheting behavior of SiC P/ 6061Al alloy composites were numerically simulated by using finite element code ABAQUS and considering different particulate shapes , and the effect of parti2cle shape on the ratcheting of the composite was discussed. The shapes of the particles are sphere , cube , short prisms and short cylinder . The result s show that for the particles with prescribed shapes , the reinforcing degree of the spherical particle to the matrix is the weakest , and it s composite produces the largest ratcheting st rain in the cyclic st ressing. For the short prismatic particle , it s reinforcing degree depends on the number of it s edges , i . e. ,the reinforcing degree of the pentagonal prism particle is the highest , and then the reinforcing degree of the short prismatic particle decreases with the increase of the edge number , and finally becomes close to that of the short cy2lindrical particle. Moreover , based on the numerical result s , the mesoscopic plastic deformation and it s evolution features of the composites were also discussed , which is very useful in studying the damage and failure mechanism of particle reinforced metal mat rix composites.