  We have performed ab-initio tensile tests of bulk Al along different tensile
axes, as well as perpendicular to different grain boundaries to determine
mechanical properties such as interface energy, work of separation and
theoretical strength. We show that all the different investigated geometries
exhibit energy-displacement curves that can be brought into coincidence in the
spirit of the well known universal binding energy relationship curve. This
simplifies significantly the calculation of ab-initio tensile strengths for the
whole parameter space of grain boundaries.
