  We present a multiscale model bridging length and time scales from molecular
to continuum levels with the objective of predicting the yield behavior of
amorphous glassy polyethylene (PE). Constitutive parameters are obtained from
molecular dynamics (MD) simulations, decreasing the requirement for ad-hoc
experiments. Consequently, we achieve: (1) the identification of multisurface
yield functions; (2) the high strain rate involved in MD simulations is
upscaled to continuum via quasi-static simulations. Validation demonstrates
that the entire multisurface yield functions can be scaled to quasi-static
rates where the yield stresses are possibly predicted by a proposed scaling
law; (3) a hierarchical multiscale model is constructed to predict temperature
and strain rate dependent yield strength of the PE.
