Before revision: The strain tensor for antiplane strain is given by Relation to infinitesimal rotation tensor The infinitesimal strain tensor is defined as Therefore the displacement gradient can be expressed as where The quantity is the infinitesimal rotation tensor (see also: infinitesimal rotation matrix).
After revision: The strain tensor for antiplane strain is given by Relation to infinitesimal rotation tensor The infinitesimal strain tensor is defined as Therefore the displacement gradient can be expressed as where The quantity is the infinitesimal rotation tensor or infinitesimal angular displacement tensor (related to the infinitesimal rotation matrix).