An initially straight cable is loaded by point masses, the cable's own
weight, and point masses. The static equilibrium and the eigenfrequencies
around the static equilibrium are computed. This test originates from an
older ADINA test case description^{[28]} and has been converted to the MKS system of units.

The cable is prestressed with an initial stress, initial strain, or
initial force (see input file `cable.mdl`

). All 3
variants are tested, checking the final deformed position and the cable
forces. The dead weights are introduced by means of point masses and
referenced in the natural boundary condition case **nbc 1**
(file `cable.mdl`

) with the terrestrial gravitational
acceleration in the proper direction, i.e. the negative y-axis. Note that
the vibration analysis case (case 2) may not reference the natural boundary
condition case **nbc 1**, because it would re-introduce the
boundary condition a second time.

The static load-displacement response of a node (node A) and the deformed configuration are shown in the figures below. Values correspond to those of the ADINA test case description.

**Figure 70. Tower Cable: Initial (blue) and deformed position in [m] at load
level 1.0. Applied forces [N] plotted in deformed configuration.**

The vibration analysis with prestress results (the equilibrium
position for the load factor 1.0) are listed in the table below. To perform
a restart with a given equilibrium solution the `dof_init`

directive has to be issued to the case defining the free vibration analysis
(here: case 2)

case 2 ... dof_init 'DISP.*.10.0.1' ... end

or in the command line to B2000++

`prompt>`

b2000++ -adir dof_init=DISP.*.10.0.1 -adir case=2 DBNAME

Mode | f [Hz] (B2000++) | f [Hz] (ADINA, see footnote) |
---|---|---|

1 | 0.226 | 0.226 |

^{[28] }K. J. Bathe; ADINA - A Finite Element Program for Automatic
Dynamic Incremental Analysis; MIT Report 82448-1 (1976).