1. Reference problem#
1.1. Geometry#
Consider an infinite tube with an inner radius of \(\mathrm{20m}\) and an outer radius of \(\mathrm{21m}\). The length of the tube is not involved in the evaluation of the reference solution, but this length is set to \(\mathrm{10m}\) for the physical modeling of the problem (illustration).

Illustration 1.1.1: Geometry of the concrete tube with a thickness of 1 m and an internal radius of 20 m
1.2. Material properties#
The concrete material is isotropic elastic whose properties are:
\(E=31000\mathrm{MPa}\)
\(\nu =0.2\)
The properties of clean creep concrete (model ULMV_FP) are given below:
K_RS = \(2.0e11\mathrm{Pa}\),
ETA_RS = \(4.0e16\mathrm{Pa.s}\),
K_IS = \(5.0e10\mathrm{Pa}\),
ETA_IS = \(1.0e17\mathrm{Pa.s}\),
K_RD = \(5.0e11\mathrm{Pa}\),
ETA_RD = \(1.0e16\),
ETA_ID = \(1.0e17\).
1.3. Boundary conditions and loads#
On edge \(\mathrm{AB}\), vertical movements along the \(Y\) axis are blocked.
On edge \(\mathrm{AD}\), a confinement pressure of \(\mathrm{1MPa}\) is imposed.
On edge \(\mathrm{BC}\), a uniform connection is imposed for all the nodes in the \(X\) direction.
On edge \(\mathrm{CD}\), a uniform connection is imposed for all the nodes in the \(Y\) direction.
Uniform bond boundary conditions ensure that an infinite cylinder is modelled and not a finite dimensional cylinder.
1.4. Initial conditions#
nought