Help Getting the force acting on a Rod

[astro.domine]

These "lambdas" are lagrange multipliers, you can convert them to forces (expressed in newtons) by dividing by the step time squared. There's an example of this in ObiRope.cs, ApplyTearing() method: it iterates over all distance constraints, calculating the force they're exerting and then selecting the ones with largest force to tear.

Actually, one more question; I don't quite understand the mathematics here well enough to know.

When reading the lambdas (Lagrange multipliers) of the StretchShear/BendTwist constraints, I see that the values flip between negatives & positives depending on the way the rod is bending. Does this mean I should be taking the absolute values when attempting to sum the total force, or should I let them counteract each other?