  In this contribution, we present a new Materials Knowledge System framework
for microstructure-sensitive predictions of effective stress--strain responses
in composite materials. The model is developed for composites with a wide range
of combinations of strain hardening laws and topologies of the constituents.
The theoretical foundation of the model is inspired by statistical continuum
theories, leveraged by mean-field approximation of self-consistent models, and
calibrated to data obtained from micromechanical finite element simulations.
The model also relies on newly formulated data-driven linkages between
micromechanical responses (phase-average strain rates and effective strength)
and microstructure as well as strength contrast of the constituents. The paper
describes in detail the theoretical development of the model, its
implementation into an efficient computational plasticity framework,
calibration of the linkages, and demonstration of the model predictions on
two-phase composites with isotropic constituents exhibiting linear and
power-law strain hardening laws. It is shown that the model reproduces finite
element results reasonably well with significant savings of the computational
cost.
