| CALC : Pipe : Wall Thickness 063 : ASME B31.8 Onshore Pipeline Restrained Expansion Longitudinal Stress : Calculator
Description : Calculate the pipeline longitudinal stress for a fully restrained onshore pipeline.
Discussion : The longitudinal stress is the sum of the axial stress and the positive and negative bending stress. Torsion Stress is neglected. Check that the magnitude of the longitudinal stress is less than the allowable stress.
References :
Calculation Steps :
- Allowable stress
- Axial and bending stress
- Longitudinal stress
Input Variables :
- α = Pipe Thermal Expansion Coefficient
- ν = Poisson's Ratio
- D = Pipe Nominal Diameter
- E = Pipeline Youngs Modulus E
- Fa = Pipeline External Force
- M = Pipeline Bending Moment
- P = Pipeline Design Gauge Pressure
- Sy = Pipeline SMYS - Specified Minimum Yield Stress
- T = ASME B31 Temperature Derating Factor
- Td = Design Temperature
- Ti = Installation Temperature
- t = Pipe Nominal Wall Thickness
Output Variables :
- Ax = Pipe Wall Nominal Cross Section Area
- ID = Pipe Nominal Inside Diameter
- S = Allowable Longitudinal Stress
- SL+ = Pipeline Longitudinal Stress Positive Bending Stress
- SL- = Pipeline Longitudinal Stress Negative Bending Stress
- Sa = Pipeline Axial Stress
- Sb = Pipeline Bending Stress
Calculation :
S = 0.9 Sy T
ID = D - 2 t
Ax = π / 4 ( D 2 - ID 2 )
Sa = ( ν P D ) / ( 2 t ) + E α ( Ti - Td ) + Fa / Ax
Sb = | ( 32 M D ) / ( π ( D 4 - ID 4 ) ) |
SL+ = Sa + Sb
SL- = Sa - Sb
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