. The critical external pressure of cylindrical tubes. Tubes; Strength of materials. -11- Table 1 contains those values of the whole number n for the above given values of a// and for intervals equal to 0,002 of the ratio h/a, which give the least critical pressure. The table is made from direct readings from and 7- Further, Table 2 also contains the magnitudes of the least critical pressures, for the same values of a// and h/a. Equation (D) is the basis for calculations, but improvements are taken into consideration with regard to the more exact equations (A) and (B). The values of p g
. The critical external pressure of cylindrical tubes. Tubes; Strength of materials. -11- Table 1 contains those values of the whole number n for the above given values of a// and for intervals equal to 0,002 of the ratio h/a, which give the least critical pressure. The table is made from direct readings from and 7- Further, Table 2 also contains the magnitudes of the least critical pressures, for the same values of a// and h/a. Equation (D) is the basis for calculations, but improvements are taken into consideration with regard to the more exact equations (A) and (B). The values of p given in the table are valid for an elastic modulus of E = 2,000,000 kg/cm^ (28 x 10 lbs. per sq. in.) and can be changed for metals with another modulus E* in the ratio E'/E. In both tables those values are cut off at the lower right hand side which correspond to stress of more than l800 kg/cm^ (25,600 ) 1 /4 A' /' 1 / 1 ' -7 / / v r^'J^ -^ M hi w "/ li y y^ 1 y / .J^ ^ --^ Jo' k S- ^^ > Fig. 7* Fig. 3 to a larger scale. lOOh 1-0 0.; 2 5 6 7 8 2 5 4 5 6 5 2 3 4 5 5 6 2 5 4 4 5 2 2 3 4 2 2 5 2 2 3 2 2 4 4 4 4 4 5 4 4 5 5 5 5 TEble 1. The number of lobes n around the circmuTerence for various wall thicknesses 2h and tube lengths 1, lOOh " r- 0 3-2 15 13 18 25 21 32 17 32 12 23 47 18 31 66 111 140 190 51 70 87 76 101 132 45 55 32 Efj- ^ 1800 (21) In the same way, a dotted line is drawn in Fig, 5» which corresponds to eq. (21), namely y = p. Table 2. Critical proasure p in kg. per aq. neaaes 21i and tube lengtha 1 for E .19 T 10-* We will return to the significance of this demarcation immediately. If the values of h, a, and / are such that the tables are not sufficient, we must determine the pressure p for various values of n from eq. (D), The determina
Size: 2519px × 992px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjectstrengthofmaterials, booksubjecttube
