Reduced-Variable Failure Correlations

FIGURE 10.7 Typical stress-strain diagrams for brittle glass (A), resilient rubber (B), and ductile plastic (C). 

FIGURE 10.8 Stress-strain data to break for two spandex fibers plotted according to Equation 9.93. Here a and a are the tensile extension ratio and stress, respectively. (Data from Higgins, T. D., Union Carbide Corporation, S. Charleston, private communication, 1969.) 

FIGURE 10.9 Schematic representation of failure envelope enclosing curves at constant strain rate. Dashed lines illustrate stress relaxation and creep under different conditions. (Data from Smith, T. L., J. App. Phys., 35, 27, 1964.) 

Failure envelopes for real polymers have been most successful for nonfilled, noncrystallizing rubbers. Efforts to find ways of generalizing the principles of superposition to a wider range of commercial rubber compounds continue [8]. 

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