Woven fabric composite material model with material nonlinearity for nonlinear finite element simulation

The objective of the current investigation is to develop a simple\ yet generalized\ model which considers the two!dimensional extent of woven fabric\ and to have an interface with nonlinear _nite element codes[ A micromechanical composite material model for woven fabric with nonlinear stress!strain relations is developed and implemented in ABAQUS for nonlinear _nite element structural analysis[ Within the model a representative volume cell is assumed[ Using the iso!stress and iso!strain assumptions the constitutive equations are averaged along the thickness direction[ The cell is then divided into many subcells and an averaging is performed again by assuming uniform stress distribution in each subcell to obtain the e}ective stress strain relations of the subcell[ The stresses and strains within the subcells are combined to yield the e}ective stresses and strains in the representative cell[ Then this information is passed to the _nite element code at each material point of the shell element[ In this manner structural analysis of woven composites can be performed[ Also\ at each load increment global stresses and strains are communicated to the representative cell and subsequently distributed to each subcell[ Once stresses and strains are associated to a subcell they can be distributed to each constituent of the subcell i[e[ _ll\ warp\ and resin[ Consequently micro!failure criteria "MFC# can be de_ned for each constituent of a subcell and the proper sti}ness degradation can be modeled if desired[ This material model is suitable for implicit and could be modi_ed for explicit _nite element codes to deal with problems such as crashworthiness\ impact\ and failure analysis under static loads