Plot the Time History of the Energy Variables

Create history plots to analyze the contact energy output variables while the arrowhead is inserted into the wall and snaps into the final position. Create a contour plot of the contact pressure to analyze the interaction of the change in the normal direction of the contact constraint with the relative motion between contact surfaces.

  1. Create an X-Y plot from history output for the following energy variables:

    Variable Description
    ALLWK External work
    ALLFD Total energy dissipated through frictional effects
    ALLCCDW Contact constraint discontinuity work
    ALLIE Total strain energy
    ALLCCE The sum of the contact constraint elastic energy in the normal direction and the contact constraint elastic energy in the tangential directions
    ETOTAL Total energy balance

    The figure below shows a complete set of nonzero energy output variables for this example.

    The most significant energies are the external work (ALLWK) and the contact constraint discontinuity work (ALLCCDW). In this example, these output variables have different signs. If the external work were modified to be ALLWK + ALLCCDW, the major energies would be approximately in balance with the combination of frictional dissipation and elastic energy throughout the simulation.

  2. Create a contour plot of the contact pressure, and step through the increments.

    The figure below shows the contact pressure at increment 4 (Left: t≈0.262s) and increment 5 (Right: t≈0.319s). At increment 4, the leading edge of the wall edge contacts the inclined surface of the arrowhead surface. At increment 5, the leading edge of the wall edge contacts the top surface causing a significant change in the normal direction of the contact constraint.



    If the normal direction of the contact constraint changes during a time increment that also has relative motion between the contact surfaces, a nonzero incremental ALLCCDW contribution can occur. This in manifested in the first significant drop in ALLCCDW between t=0.2 and t=0.4 in the X–Y plot shown earlier.

  3. Save your work.