. Transactions. the recorded pressures corre-sponding to the measured diameters were too high. It is possible, how-ever, to estimate, from the behavior on the next application of pressure,that a maximum pressure of 78,000 lb. per sq. in. (5483 kg. per sq. cm.)was reached on the first application. The probable course of the truecurve between 55,000 and 78,000 is shown dotted in the figure. A totalset of in. ( mm.) on the outside diameter was produced by thefirst application. The feature of particular interest in Fig. 4 is that thereis no evidence of an elastic limit anywhere, on inc
. Transactions. the recorded pressures corre-sponding to the measured diameters were too high. It is possible, how-ever, to estimate, from the behavior on the next application of pressure,that a maximum pressure of 78,000 lb. per sq. in. (5483 kg. per sq. cm.)was reached on the first application. The probable course of the truecurve between 55,000 and 78,000 is shown dotted in the figure. A totalset of in. ( mm.) on the outside diameter was produced by thefirst application. The feature of particular interest in Fig. 4 is that thereis no evidence of an elastic limit anywhere, on increasing pressure, but thestress-strain curve from the beginning shows pronounced curvature. 154 EXPERIMENT IN ONE-PIECE GUN CONSTRUCTION This is not surprising in this material, which could not have been leftby the forging in a state of complete ease. The linear relation to be expected between stress and strain in a cyl-inder of these dimensions may be computed from the theory of elasticity . tt*^ 0 10 20 30 40 50 60 70 80Pressure Fig 4 —First application of pressure to the breech. The increase of OUTSIDE DI.^METER (oRDINATE) IS SHOWN IN INCHES AGAINST THE INTERNAL PRESSURE(.\BSCISSA) in OF POUNDS PER SQUARE INCH. as given in any textbook. (See, for example, Loves Elasticity, ) We have for the radial displacement U, U = Ar + B A = pri Xe 2(X+70(^o - ri^) 2(X + fx) B = pr oVi^ 2n{ro - ri^) where p is the internal pressure, ri internal and ro external radius, X andn the two elastic constants. The longitudinal strain of the cylinder eis connected w^ith the longitudinal fiber stress Zz by the relation Z. = X pri + e (3X + 2fx)n Abs. C. G. S. units, X + /i >o - rx X + A»Id a cylinder mounted, as this was, so that the thrust on the end plugs wastaken by an outside frame, we have, neglecting friction, Z, = as average values for the elastic constants of steel M = X W X = X 1012we find that e = - X 10 for 100,000 lb. per
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
