I experimentally compared Unreinforced and Reinforced brick masonry. The ductility is calculated from the backbone curves. The Unreinforced masonry showing more ductility because of formula Ultimate/yield (very small yield deformation), although the load drop is excessive. The reinforced masonry looks more ductile but due to ultimate/yield its theoretical value is less.

Similarly one of the specimen yield near to zero deformation so any thing divided by small value is very big value.

Is there any solution to this?