Strength ratio

Fig. 27.2. The Volkswagen Passat - a typical 1970s pressed-steel body with no separate chassis. For a given material this monocoque construction gives a minimum weight-to-strength ratio.

Fig. 27.6. A 1 932 Rolls-Royce. Mounted on a separate steel chassis is an all-aluminium hand-beaten body by the famous coach building firm of James Mulliner. Any weight advantage due to the use of aluminium is totally outweighed by the poor weight-to-strength ratio of separate-chassis construction but the bodywork remains immaculate after 48 years of continuous use ...

Drill Collar Number Outside Dia, D Bore, +A -0 i Length, ft, 6 in. L Bevel Dia. A D, Bending Strength Ratio... 

The Temperature Dependence of the Angle Relation, Transition Dipole Strength Ratio, and Transition Dipole Orientation of the Chromophores in the K26.Phe-a RCs... 

Figure 3 displays the splittings and the shifts of the D- and C- lines of aluminum and of the D-line of the A(D,C)2 series with uniaxial stress in the three major orientations. Whereas the lines of the elemental acceptor split for [111] stress symmetrically into four lines about the zero stress position, the D-line of A(D,C)2 separates into two components only. They exhibit a relative strength ratio of 3 1 and energy shifts of 1 3 about the... 

Layup Young s modulus (GPa) Measured stress concentration factor Predicted stress concentration factor Notched strength, [Pg.344]

Fig. 3.38 The creep of plain and air-entrained concretes at 21°C and a stress-strength ratio of 45% (Nasser).

Fig. 27. Quantum efficiency of sensitized hole injection in organic crystals (injected holes per incident photon) versus applied field strength (ratio of voltage to crystal thickness) Pe = perylene. Ar = anthracene, Ch = chrysene, Phen = phenanthrene...

Tough materials with sufficient high elongation at rupture - in the minimum 10 % - and with a good ratio between allowed yield strength and the tensile strength-ratio of approximately 0.85 and better should be chosen. The cooperation with a experienced steel manufacturer is an important link in the design process. 

The endurance limit for smooth test specimens run in normal atmospheres at room lemperature is an ideal or limiting value. In ihe case of steels not hardened, or heat-iremed lo moderate hardness, the smooth specimen endurance limit is approximately one-half of the tensile strength The endurance limit-tensile strength ratio is less than one-half lor many other materials. 

Malerials with very high internal surfuee areas may absorb a measurable amount of moisture even a monomoleeulur thickness of moisture on a large area becomes readily measurable. However, exposure lit high relative humidity will not saturate" the material, and as relative humidity changes so will the absorbed moisture. Some materials are tested wet to indicate wet to dry strength ratio. 

Table 13.12 permits a comparison of the values of the tensile, flexural and compressive strength. The strength ratios of polymers are compared with those of other materials in Table 13.13. Obviously there is a strong influence of the Poisson ratio on the value of the compressive/tensile strength ratio. The following empirical equation provides a good estimate (see Fig. 13.63) ...

On the other hand, the flexural/tensile strength ratio is nearly constant (average value 1.6) for polymers. (The same is true for the flexural/tensile modulus ratio). 

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