Subject thermal strength

Tjeerdsma etal. (1998a) subjected thermally modified wood to soft rot decay in unsterile soil tests. Although decay resistance was enhanced by thermal treatment, it was not possible to prevent attack entirely. Treatments giving the best performance in terms of decay resistance also exhibited the highest strength losses. Viitanen etal. (1994) have also reported on some preliminary experiments on heat-treated wood in unsterile soil. 

In addition to the geometric factors (shape and wall thickness), the material properties a, E, andju. decisively influence the thermal strength of glasses subjected to temperature variations and/or thermal shock. Thermal loads in similar articles made from different glasses are easily compared by means of the characteristic material value... 

The reactor barrel extracted from the mono-block after the spent fuel has been reloaded is subject to changes in shape depending upon resistance of the basket material to fast neutron fluence and the effects of thermal strength therefore, the possibility of a repeated use of the basket needs to be validated. 

Table 3 provides recommended start-up and shut-down procedures. Effort should be made to avoid subjecting units to thermal shock, overpressure, and/or hydraulic hammer, since these conditions may impose stresses, that exceed the mechanical strength of the unit or the system in which it is installed, which may result in leaks and/or other damage to the unit or entire system. 

Example 2.21 A rod of plastic is subjected to a steady axial pull of 50 N and superimposed on this is an alternating axial load of 100 N. If the fatigue limit for the material is 13 MN/m and the creep rupture strength at the equivalent time is 40 MN/m, estimate a suitable diameter for the rod. Thermal effects may be ignored and a fatigue strength reduction factor of 1.5 with a safety factor of 2.5 should be used. 

The emission of thermal electrons is subject to statistical fluctuations (lead shot effect). It is influenced by the current strength, the number of electric charges hberated and the frequency of the radiation [55] (see [40] for further details). 

A laminate can be subjected to thermal, moisture, and mechanical loads with the objective of surviving those loads. A method of strength analysis is required to determine either (1) the maximum loads a given laminate can withstand or (2) the laminate characteristics necessary to withstand a given load. The maximum loads problem is, of course, an analysis situation, and the laminate characteristics problem is a design situation that will be discussed in Chapter 7. 

For some purposes where the strength and ductility of steel are not prerequisites, other metals or materials may be used to advantage, particularly when the component or article is not a load-bearing one. Some of the non-ferrous metals and plastics materials are extremely useful in this respect, especially the latter with their excellent corrosion-resistant properties and ease of formability. Non-ferrous metals in sheet form are often used as roof covering. In such situations they could well become subject to condensation. Condensation could be the result of thermal pumping or internal conditions. Under conditions in which condensation can occur, copper is not normally attacked, but lead, zinc and aluminium may be attacked and corrode from the inside of the building outwards. 

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