COMPUTATIONAL THERMOPLASTICITY OF LARGE DEFORMATIONS BEHAVIOR BASED ON MULTISCALE METHODS

U radu je prezentirana metoda višerazinskog modeliranja termoplastičnih deformacija heterogenih materijala primjenom računalne homogenizacije prvoga reda. Koncept analize koja se vrši na makro i mikro razini sastoji se od prijenosa naprezanja i varijabli stanja s jedne razine na drugu. Problem se na mikrorazini tretira kao izoterman, dok je na makrorazini isti neizoterman. Korištena je teorija velikih plastičnih deformacija. Razvijen je model reprezentativnog volumenskog elementa (RVE) na koji su primijenjeni periodični rubni uvjeti. Rješavanjem problema rubnog uvjeta (BVP) dobiven je numerički konstitutivni zakon koji daje odnos između naprezanja i deformacije u svakoj integracijskoj točki makrorazine. Numerička procedura razvijena je za probleme ravninskog stanja deformacije i temelji se na teoriji prvog reda. Procedura je verificirana na više primjera i doneseni su odgovarajući zaključci.This paper presents the multiscale modeling of thermoplastic deformation of heterogeneous materials by using the first-order computational homogenization. The concept of the analysis at the macro and microscale consists of transfer of stress and the state variables from one level to another. The problem at the microscale, is treated as isothermal, while at the macroscale as non-isothermal. The theory of large plastic deformation has been used. A model of a representative volume element (RVE) has been developed, on which periodic boundary conditions have been applied. By solving the boundary value problem (BVP), numerical constitutive law was obtained, that gives the relation between stress and strain in every integration point at the macroscale. Numerical procedure was developed for the problems of the plane strain condition and it is based on the theory of the first order. The procedure was verified at several examples and appropriate conclusions were adopted