Repeated straining

Plastics, including polymer blends, are relatively high damping and low thermal conductivity materials. Thus, repeated straining of an article leads to a temperature rise within and throughout its body. Rapid stress-strain cycling can significantly heat up the article and thereby induce thermal failure — the phenomenon is frequency-dependent. Where the thermal effect is to be minimized, much lower frequencies, of the order of a few Hz, should be employed. 

Finally, the conclusion of Koppanyi and Avery [6] should be repeated Strains and different species, including Homo, may differ in the rate of turnover and metabolic degradation of drugs. These differences can be measured by the methods of essential elimination as well as by chemical or biochemical techniques. Such studies may permit a limited extrapolation from experiments on lower animals to drug effects in the human species. ... 

Repetitive Strain Injury—Injury caused by repeated strains. 

Elastomers are a class of polymers that can be repeatedly strained and then return to the approximate original length on release of the load. Traditional elastomers such as rubber are able to achieve this elastic behavior by having a low glass transition temperature and a small number of chemical crosslinks that form a permanent network... 

Figure 20 shows the cyclical characteristics curves considering the peaks of the different hysteresis cycles for 20 kN and 40 kN panels. Each characteristic curve is just the constitutive law of the respective panel it is the one that should be considered if the panel is subject to repeated strain over time, as in the case of an earthquake. This curve shows what was previously stated about the hysteresis loops, namely that the panel has an overall non-linear behavior due to the dissipative phenomena. 

Fig. 9 Nominal engineering stress-strain curves of a lightly oriented HBA/HNA TLCP extrudate tested until failure (1) and of a second sample tested under conditions of repeated strain until failure (2-8). Curves shifted equally along the x-axis by 0.25% in (a) and unshifted in (b). (From Ref. 46.)...

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