hardness is measured by hardness test and it is kind of related to strength. Higher strength, higher hardness, generally. You can't use hardness number in simulation and there are micro and macro hardness testing methods. strength is a general term, there are yield strength, ultimate tensile strength, etc usually measured by tensile test. Stress-strain curve is the basic requirement to run simulation. Brittle = poor toughness. Ductile generally means good elongation in tensile test, not necessil