Benham

N. R. Smith, User s Guide to Industrial Diamonds, Hutchinson Benham, London, 1974, pp. 27—72. 

Benham, P. P. and Warnock, F. V. 1983 Mechanics of Solids and Structures. London Pitman. 

Benham, P.P. Crawford, R.J. and Armstrong, C.G Mechanics of Engineering Materials, Longmans (1996)... 

Note that these stress, strain and modulus equations are given for illustration purposes. They apply to three-point bending as shown in Fig. 2.3. Other types of bending can occur (e.g. four-point bending, cantilever, etc.) and different equations will apply. Some of these are illustrated in the Worked Examples later in this chapter and the reader is referred to Benham et al. for a greater variety of bending equations. 

The bulk modulus is appropriate for situations where the material is subjected to hydrostatic stresses. TTie proof of equations (2.15) and (2.16) is given by Benham et al. 

Solution The top of the bottle cap is effectively a plate with clamped edges. The central deflection in such a situation is given by Benham et al. as... 

The nylon ring may be considered as a thick wall cylinder subjected to this internal pressure (see Appendix D). At the inner surface of the ring there will be a hoop stress, <7, and a radial stress, Cr. Benham et al. shows these to be... 

The first step in the analysis of this situation is the transformation of the applied stresses on to the fibre axis. Referring to Fig. 3.10 it may be seen that Ox and Oy may be resolved into the x, y axes as follows (the reader may wish to refer to any standard Strength of Materials text such as Benham, Crawford and Armstrong for more details of this stress transformation) ... 

Treating the bush as a thick wall cylinder subjected to this value of external pressure, then Benham et at. show that at the outer surface of the bush, the stresses are ... 

Laister and Benham have shown that under more arduous conditions (immersion for 6 months in sea-water) a minimum thickness of 0-025 mm of silver is required to protect steel, even when the silver is itself further protected by a thin rhodium coating. In similar circumstances brass was completely protected by 0 012 5 mm of silver. The use of an undercoating deposit of intermediate electrode potential is generally desirable when precious metal coatings are applied to more reactive base metals, e.g. steel, zinc alloys and aluminium, since otherwise corrosion at discontinuities in the coating will be accelerated by the high e.m.f. of the couple formed between the coating and the basis metal. The thickness of undercoat may have to be increased substantially above the values indicated if the basis metal is affected by special defects such as porosity. 

Judith L. Benham 3M Specialty Chemicals Division St. Paul, MN 55144... 

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