True stress at break

Appendix B General Properties and Data on Elastomers and Plastics 175 Table B.IO True Stress at Break of Selected Melt-Mixed Rubber-Plastic Blends ... 

B.IO True stress at break of selected melt-mixed rubber-... 

Figure 5. True stress-at-break plotted on doubly logarithmic coordinates against the strain-at-break. Conditions 30°C extension rates from 9.4 X 103 to 9.4 min 1. Quantity A introduced for clarity.

Data are presented which illustrate that the tensile strength and elongation-at-break depend significantly on the extension rate even when the stress remains in equilibrium with the strain prior to fracture. A crude estimate was made of the threshold (lowest possible) values of the true stress-at-break and the elongation-at-break for the TIPA elastomer. The estimated quantities are about 26% less than those found at an extension rate of about 0.01 min-1 at 30°C. 

To obtain the true stress at break, (in Fig. 4.2 and 4.3), tensile strength values were multiplied by the extension ratio = I to, where Z and Zo are the extended and original PU sample lengths and the true strain true X elongation at break, e (e = X +1). 

Fig. 3. Composite curve of true stress at break Xbtxb at 40°C vs reduced time to break...

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