For the material illustrated, the volume fraction of the ductile matrix is large enough that it can take the increased load without failing. The composite continues to deform along the matrix ...

These are nonlinear elastic materials for which the slope of the stress-strain curve, (ds/de ... until the yield stress of the material if it is ductile, after which the material plastically deforms.

The highest point of the stress–strain curve is the ultimate tensile strength ... Tensile strengths are rarely of any consequence in the design of ductile members, but they are important with brittle ...