Calculate Hobbs upheaval and lateral buckling load and buckling temperature from initial out of straightness for multi layer pipelines.
Buckle conditions can be calculated for either buckle initiation, or post buckle for the selected buckle mode. The global axial load should be the same for buckle initiation and post buckle. Buckling should be checked for lateral buckling modes 1, 2, 3 and 4, and for upheaval buckling. The lowest buckling temperature should be used. Post buckle results are indicative only. The model is not valid outside the elastic range. This calculator is suitable for unburied pipelines lying on the sea bed. It should not be used for buried pipelines.
Tool Input
- schdtype : Line Pipe Schedule Type
- diamtype : Line Pipe Diameter Type
- ODu : User Defined Outside Diameter
- IDu : User Defined Inside Diameter
- wtntype : Line Pipe Wall Thickness Type
- tnu : User Defined Wall Thickness
- wltype : Pipe Unit Weight Type
- sectype : Cross Section Type
- OODu : User Defined Outer Diameter Including Coatings)
- Zu : User Defined Pipe Z Modulus
- EIu : User Defined Pipe E x I
- EAu : User Defined Pipe E x A
- EAαu : User Defined Pipe E x A x alpha
- νu : User Defined Pipe Poisson's Ratio
- WLu : User Defined Pipe Total Weight Per Length
- buckmode : Buckle Mode
- buckstage : Buckle Stage
- WTi : Pipe Liner Wall Thickness
- ρi : Pipe And Liner Density
- Ei : Pipe And Liner Elastic Modulus
- αi : Pipe And Liner Thermal Expansion Coefficient
- νi : Pipe And Liner Poisson's Ratio
- WTo : Pipe Coating Wall Thickness
- ρo : Pipe Coating Density
- Δi : Initial Out Of Straightness
- Ta : Ambient Or Installation Temperature
- Pi : Internal Pressure
- Nin : Installation Load
- ρf : Internal Fluid Density
- ρb : External Fluid Density
- μa : Axial Friction Factor
- μl : Lateral Friction Factor
Tool Output
- ΔT : Delta Temperature At Buckle Inititation
- Δb : Buckle Amplitude
- ν : Pipe Poisson Ratio
- BM : Maximum Bending Moment (Elastic)
- EA : Pipe E x A
- EAα : Pipe Expansion Modulus
- EI : Pipe E x I
- Fab : Buckle Axial Load
- Fag : Global Axial Load (Away From Buckle)
- IID : Pipe Inside Diameter Including Liner
- Lb : Buckle Half Wave Length
- Ls : Buckle Slip Length
- OD : Line Pipe Diameter
- OD/tn : Line Pipe Diameter Over Wall Thickness Ratio
- OOD : Pipe Outer Diameter Including Coatings
- SB : Maximum Bending Stress (Elastic)
- Tb : Buckle Inititation Temperature
- W : Total Pipe Weight Per Unit Length
- Z : Pipe Z Modulus
- cvg : Convergence Check
- mlb : Buoyancy Unit Mass
- mlc : Contents Unit Mass
- mlp : Pipe Unit Mass Including Liner And Coating
- tn : Line Pipe Thickness