Disarrangements in continua and the geometry of microstructure

Abstract: "The term 'disarrangement' is proposed here to describe geometrical changes either at the macroscale or at the microscale that are not accounted for by the classical deformations employed in continuum mechanics. Collections of non-classical deformations studied by Del Piero and Owen (1993) are then described in order to give a more precise context for the term 'disarrangement'. Examples of disarrangements both at the microscale and at the macroscale are presented, including disarrangements in liquid crystals, metallic crystals, and mixtures of continua. It is shown that volume-preserving deformations that are limits of discrete translations in crystallographically preferred directions necessarily are 'piecewise-shearing deformations'."