This is an animation of an Abaqus/Standard simulation of a rubber strip being dragged along
a rigid channel. The wires seen in the animation are axial connector elements with field-variable-dependent stiffnesses and 
constitutive reference lengths. A field variable is used to increase and then decrease the connector stiffness in a sequence that
drags the strip along the channel. The strip is connected to the channel with no-separation frictionless contact. 
The variable SHEAR which is plotted in the animation is equal to the maximum principal value of the logarithmic
strain minus the minimum principal value of logarithmic strain, i.e. LEP3-LEP1 in terms of Abaqus output variables. 
The Physics Results Explorer app has the Field Expression Manager which can create the SHEAR variable frame by frame from
the output variable LE. SHEAR is approximately equal to the maximum orthogonal shear.