(a) An independent tank type B designed from bodies of revolution must have allowable stresses
3
determined by the following formulae:
3 See Appendix B for stress analyses definitions.
σm≤f
σL≤1.5 f
σb≤1.5 F
σL + σb≤1.5 F
σm + σb≤1.5 F
where:
σm = equivalent primary general membrane stress
4
4 See Appendix A for equivalent stress.
σL = equivalent primary local membrane stress
4
σb = equivalent primary bending stress
4
f = the lesser of (σB/A) or (σY/B)
F = the lesser of (σB/C) or (σY/D)
A, B, C, and D = stress factors in Table 2.
Table 2—Values for Stress Factors
|
| Nickel steel and carbon manganese steel values
| Austenitic steel values
| Aluminum alloy values
|
|---|
| Stress factors:
| | | |
| A | 4.0 | 4.0 | 4.0
|
| B | 2.0 | 1.6 | 1.5
|
| C | 3.0 | 3.0 | 3.0
|
| D | 1.5 | 1.5 | 1.5 |
(b) An independent tank type B designed from plane surfaces must have allowable stresses specially approved by the Commandant (CG-ENG).
[CGD 74-289, 44 FR 26009, May 3, 1979, as amended by CGD 82-063b, 48 FR 4782, Feb. 3, 1983]
source: CGD 74-289, 44 FR 26009, May 3, 1979, unless otherwise noted.
cite as: 46 CFR 154.447