Temporary stress

Let us consider some definitions and their application to glass some aspects of transient or temporary stresses and of permanent stresses. 

As soon as the temperatures in the plate are equalized, the type of stress considered so far is relieved, and is therefore called the temporary stress. 

The danger of temporary stress lies in the fact that too fast cooling may bring about fracture when the tensile strength of glass has been exceded. Permanent stress may lead to the same consequence in the final stage of temperature equalization. Badly distributed permanent stress, which always includes its tensile component, will reduce the final strength of the ware and thus impair its value. 

More rapid cooling to ambient temperature at a rate limited by the formation of temporary stress. 

In general, the heating rate during the initial portion of the annealing schedule is relatively unimportant. Temporary stresses arising from a... 

In order to calculate the stress fixity ratio and stress recovery ratio, we also need to define the pre-stress and the fixed temporary stress. Taking the stress-strain behavior during colddrawing programming as an example, both the stress and strain can be divided into several components, as shown in Figure 5.28. Similar to the definition of pre-strain, we can define the pre-stress as the peak applied stress, that is, stress at the end of the loading step (step 1), <7p. The challenge is how to define the fixed stress. 

The rise of ascorbic acid in the plasma in temporary stress is considered by some to constitute the most reliable index of stress, although it is somewhat less sensitive than eosinophilia. Ascorbic acid con-... 

---