Proof strength

Tensile proof strength = 0.6 to 0.8 Figure 30.1 Stress-strain curve... 

The proof strength at which the volatility curve of a particular component intersects that of ethyl alcohol indicates that proof at which the minor constituent will be concentrated in a fractionating column at the limiting condition of total reflux. For practical conditions, the maximum concentration of a particular congener or minor component occurs at a proof in the column at which its volatility is approximately equal to the internal reflux ratio (L/V where L is the molal liquid or overflow rate and V the molal vapor rate). This can be established by the technique... 

It will thus bo seen that 5 gallons should be taken from the low proof spirit, and the same quantity of spirit added at above proof, iu order to raise it to proof strength. 

Grade no. Heat treatment condition Tensile properties of flat produc Min. yield strength or 0.2% proof strength (MPa) s < 25 mm in thickness Ultimate tensile strength (MPa) Min. fracture elongation As (%)... 

The yield strength (YS) of a material, denoted or is the stress corresponding to the end of the linear portion of the stress-strain curve for the uniaxial tensile test. The 0.002 (or 0.001) proof strength (i.e., 0.2% offset yield strength) is used when the material shows no pronounced yield point. Afterward any additional stress leads to a residual permanent deformation of the material i.e., plastic deformation) indicated by a hysteresis. 

For class 4.6 metric steel bolts, the proof strength is 225 MPa. The load determined in Eq. (10.6) when divided by this proof strength gives the required bolt area as 741 mm. ... 

As at these dilutions the apparent proof strength and refraction of mixtures of the low er alcohols and acetone are practically the sum of those due to each of the ingredients, when two known substances only are present, the quantities of each can be calculated from these two figures. With more than two substances present, allowance can be made for any ingredients which can be separately determined. An instance cited in the paper is the estimation of mixtures of ethyl and wopropyl alcohols and acetone by regulated oxidation of the first two entirely to acetic acid and acetone respectively, the acetone being unappreciably affected under the selected conditions. 

This indicates that the proof strength was maintained 10% throughout the reported period of 6 years. It also implies that there is no indication at 6 years of imminent change. 

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