INELASTIC DESIGN OF MMCS WITH LAMELLAR MICROSTRUCTURE

摘要

The purposes of this paper are the optimal design and modeling of inelastic behavior of MMCs with lamellar microstructure. The material under consideration consists of two phases: ceramic (Al_2O_3) and aluminium alloy (Al12Si). For modeling of the elasto-plastic behavior of the metal the J2 flow theory was used. The brittle damage model was used for modeling of the ceramics failure. A single domain of this material with preferred orientation of lamellae was modeled using FE analysis and homogenization procedure. Results of the modeling were verified by comparing with experimental data and good correspondence between obtained results was observed. The optimization problem for the determination of the sample microstructure with minimal compliance was formulated. The design variables of the posed problem are local orientation of the lamellar domains and the local volume fractions of ceramic in the domain. Solution of the optimization problem is carried out for a prescribed global volume fraction of the ceramic in the whole specimen. Resulting optimal microstructures were obtained for different geometries of the specimen and for different loading cases. The obtained results show that the optimal microstructure design obtained using inelastic model is partially different from the elastic one.