Tearing energy effects

All sorts of accidents (the sudden collapsing of bridges, sudden explosion of steam boilers) have occurred - and still do - due to this effect. In all cases, the critical stress - above which enough energy is available to provide the tearing energy needed to... 

Effect of Tear Rate and Test Temperature on Tear Energy Gc. 13... 

In general, economic inefficiency in resource allocation would be the result of a divergence between private benefits or costs and social benefits or costs, i.e. the result of externalities. Private costs (or internal costs) are directly taken by the buyer. Private costs for a transport user would, for example, include expenses for wear and tear, energy cost of vehicle use, transport fares, taxes and charges, as well as welfare effects such as own time costs. 

Figure 5.5 Effects of tear rates and temperatures on tearing energy (a) unfilled vulcanized NR, (b) black-filled vulcanized SBR.

Figure 5.6 Tearing energy T vs knot diameter d showing the effect of tear rates on the size of knot diameter formed at 23 °C. The straight line shows the tearing energy-tip diameter relationship obtained from T ...

Figure 5.12 The effect of degree of crystallinity and glass transition temperature on development of knotty tearing energy as a function of tear rate at 23 °C. (Reproduced from ref. 8).

Effect of set introduced during second-stage vulcanization on tearing energy of vulcanized black-filled NR. 

Effect of set on tearing energy of conventional cured black-filled NR vulcanizate at 24 °C and crosshead speed 100 mm/min. 

Figure 5.29 Effect of pre-straining on tearing energy at the same crack-growth rate, dc/dAi —2x 10 cm/s.

Yanyo, L. C. Kelley, F. N., Effect of Chain Length Distribution on the Tearing Energy of Silicone Elastomers. Rubber Chem. Technol. 1987,60, 78-88. 

A study was made of gas decompression failures in elastomeric seals using a fracture mechanics approach with considerations of gas permeation. An equation is proposed for the tearing energy associated with crack growth from internal gas bubbles in a finite thickness elastic media. The effects of gas pressure, temperature, rate of decompression and mechanical strain were studied for a range of elastomers used in oil and gas sealing applications. A theoretical treatment is presented based on a fracture mechanics criterion for fracture from an internal disc shaped flaw in a thick elastic medium. Permeation theory provides a quantification of the amount of gas available internally to initiate failures. 21 refs. 

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