Linear elastic method
This is the default method if no other options are activated. The pipeline is considered to behave completely linear elastically; the bends behave linear and have an initial stiffness (“infinite” or “limited” bend angle option available). Only the soil is modelled to behave in a non-linear elastic way and as a result a series of iterations will result to fulfill the soil curves conditions. If the soil curves are bilinear and the displacements remain within the elastic range of the soil, there will be only one iteration, being the final calculation. The same occurs if the pipeline is defined completely 'above ground'.
The bend angle may be specified as 'limited', meaning that the stiffening influence of connecting straight pipes to a bend with relatively small bend angle will be taken into account. In the figure the first order approximation has been shown for reference.
Example of influence of limited bend angle (WT bend = WT pipe)
LinearElastic, last changed: 1/31/2020