Modulus of elasticity compression

Tables 12-14 present standard values for other properties of oxides, nitrides, and carbides. In addition to the crystal system and melting point, these tables list density, hardness, modulus of elasticity, compressive strength, bending strength, fracture toughness, thermal conductivity, and thermal expansion.

Fig. 4. The immediate effect of temperature on the modulus of elasticity of clear wood, relative to the value at 20°C. The plot is a composite of studies on the modulus as measured in hen ding, in tension parallel to grain, and in compression parallel to grain. VariabiUty in reported results is illustrated by the...

Mechanical Properties. Measuremeat of the mechanical properties of diamoad is compHcated, and references should be consulted for the vahous qualifications (7,34). Table 1 compares the theoretical and experimental bulk modulus of diamond to that for cubic BN and for SiC (29) and compares the compressive strength of diamond to that for cemented WC, and the values for the modulus of elasticity E to those for cemented WC and cubic BN. 

Modulus of elasticity (E) the ratio of the unit stress to the unit strain within the proportional limits of a material in tension or compression. Refer to Figure 30.1. 

The stress-strain behavior of plastics in flexure generally follows from the behavior observed in tension and compression for either unreinforced or reinforced plastics. The flexural modulus of elasticity is nominally the average between the tension and compression moduli. The flexural yield point is generally that which is observed in tension, but this is not easily discerned, because the strain gradient in the flexural RP sample essentially eliminates any abrupt change in the flexural stress-strain relationship when the extreme fibers start to yield. 

The test can provide compressive stress, compressive yield, and modulus. Many plastics do not show a true compressive modulus of elasticity. When loaded in compression, they display a deformation, but show almost no elastic portion on a stress-strain curve those types of materials should be compressed with light loads. The data are derived in the same manner as in the tensile test. Compression test specimen usually requires careful edge loading of the test specimens otherwise the edges tend to flour/spread out resulting in inacturate test result readings (2-19). 

FIG. 12 Plots of elastic compressibility modulus (a) per unit area, Y and (b) that per chain, Y, of 2C18PLGA(48) brushes as a function of chain density F. The ionization degree of the carboxylic acid group, a, is also plotted in part b. 

Smith, 1971 Hannah Smith, 1971 Powers, Farah Craig, 1976). The modulus of elasticity in compression is 12 to 13 GPa (Table 6.4) (Powers, Farah Craig, 1976 Wilson, Paddon Crisp, 1979). 

Concret does not have well defined elastic and plastic regions due to its brittle nature. A maximum compressive stress value is reached at relatively low strains and is maintained for small deformations until crushing occurs. The stress-strain relationship for concrete is a nonlinear curve. Thus, the elastic modulus varies continuously with strain. The secant modulus at service load is normally used to define a single value for the modulus of elasticity. This procedure is given in most concrete texts. Masonry lias a stress-strain diagram similar to concrete but is typically of lower compressive strength and modulus of elasticity. 

DYNAMIC COMPRESSION MODULUS OF ELASTICITY IN OPEN-CELLED POLYETHYLENE FOAMS... 

The relationship between the compressive strength and the modulus of elasticity for a number of similar concretes is shown in Fig. 3.29 [35] and Fig. 3.30 [33]. Again it is clear that the presence of entrained air does not alter the normal relationship. 

Fig. 3.29 The relationship between the compressive strength and modulus of elasticity of plain and air-...

The data available on the effect of accelerators on the flexural and tensile strengths and the modulus of elasticity are limited [22, 30, 31] and are relevant only to calcium chloride and triethanolamine. The data generally point to either no effect or a slight reduction in all three properties. Also, in view of the increase in compressive strength, it is reasonable to assume that for a given compressive strength, the presence of calcium chloride or triethanolamine will reduce the flexural and tensile strengths and the modulus of elasticity. 

Physical properties of CSA-contaming concretes (compressive strength, creep, modulus of elasticity and durability) are comparable to those of corresponding Portland cement concretes, especially when CSA is used at dosages of 8-11%. When the dosage exceeds the ranges mentioned above and no restraint is provided either internally (by reinforcement) or... 

Figure 7.11 Overlay of contour plots for apparent modulus of elasticity in compression ( c)> maximum tension force (Ft) and first-cycle relaxed force (Fri). The shaded area represents optimum conditions.

Material Form or Treatment Modulus of Elasticity (GPa) Flectural Strength (MPa) Compressive Strength (MPa) Poisson s Ratio Density g/cm ... 

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