Relation between initial tensile

Fig. 13.102 shows this theoretical relation between the tensile strength and the initial modulus of PpPTA fibres for five values of ft varying from 0.10 to 0.12 rad (i.e. from 5.7 0 to 6.9 °) and for yd = 1.8 GPa and ech = 240 GPa (see Table 13.18). A rapid increase in strength of PpPTA is observed in the modulus range from 40 to 80 GPa and there the best fit agrees with j> = 0.115. For higher moduli the tensile strength levels off. This is also the case with the theoretical curves, but not until a modulus of 110 GPa (not shown here). 

FIG. 13.102 PpPTA yarn data showing the relation between tensile strength and initial modulus together with the curves calculated with Eq. (13.171) for five different values of critical shear strain, P from left to right P = 0.12, 0.115, 0.11, 0.105 and 0.10 rad used values are gd = 1.8 GPa and ecu = 240 GPa (see Table 13.18). Constructed from Figs. 22 and 23 in Northolt et al. (2005). The points above ( ) and below (O) the line for P — 0.11 are from different sets of PpPTA fibres. 

A 15 m long 1 mm-diameter wire of hardened steel is by a reversible, adiabatic elongation subjected to a tensile force F, that increases from Fi = ON in its initial state (1) to F2 = GOON in its final state (2). The stress-strain relation for the steel is given by the following relation between stress cr (MPa) and strain e... 

---