Ductility and Stiffness

[PEin2010]

Are ductility and stiffness not related? Is it true that the less stiff a member is, the more ductile it is?

 

[civilized_naah]

Are ductility and stiffness not related? Is it true that the less stiff a member is, the more ductile it is?

Flexibility is the inverse of stiffness. Flexibility is the response (deformation) to a load. Ductility relates to the RANGE of deformation that a material exhibits, not just the direct response to a particular load.

 

[MA_PE]

ductility refers to the elongation that a material can undergo after it has yielded or exceeded its elastic range. Stiffnes is the ratio of load vs deformation and can be used to describe either the elastic or plastic (after yield) ranges. If you look at a basic tensile load vs deflection curve, stiffness would be the slope of the curve at any point along the curve and ductility refers to the length of the curve after the yield point to failure.