Returns/sets the allowable stresses as the HMatrix object.
LabelBlockSA.AllowableStress ( [which As QfStressSign] ) As HMatrix
Allowable stresses are only used in the postprocessing stage to calculate the Mohr-Coulomb, Drucker-Prager, and Hill criteria. You don't need to define allowable stresses, if these criteria are of no interest to you.
Use an optional which parameter that can be qfTensile or qfCompressive if tensile and compressive allowable stresses are different.