True Axial Stress-Strain Relation

The tme stress versus tme strain curves obtained at room temperature under uniaxial tension with all the materials are displayed in Fig. 19.14. By means of the video- 

After the yield point at cTy = 29 MPa, the neat PP (51 wt% crystalline in this case) exhibits a small but significant true stress drop followed, for strain larger than about 0.3, by a progressive (although moderate) hardening. 

As for the neat PA6, it experiences a characteristic double yield (probably due to residual humidity) and starts its steady-state plastic regime at an upper yield stress of about 50 MPa. 

---

True Axial Stress versus Strain Relation... 

---