Numerical modeling thermo-hygro-mechanical coupling of cross-ply laminate composites using a nonlocal discrete approach

Laminate composites are widely used in various industrial applications and are frequently subject to extreme temperature and moisture environment. This paper presents numerical modeling thermo-hygro-mechanical coupling of cross-ply laminate composites using a nonlocal discrete approach formulated based on the local continuum mechanics theory. In the developed model, the material domain is modeled as an assembly of regularly packed material particles whose interaction with neighboring material particles via bonds is nonlocal. Bond parameters are derived based on equivalency of energy and diffusing material transfer rate between the discrete descriptions and their continuum counterparts. The orthotropy of material properties is modeled using rotation of discretization lattice rather than the coordinate transformation that used in the local continuum mechanics theory. The interface and its effect on the material response are investigated by assigning different parameters to bond straddling different material phases. Numerical verification using single and four-ply laminate composites shows excellent accuracy of the developed model.