# Spline Stiffness Block

Spline stiffness blocks store the static stiffness properties of a bushing. The data
is stored in a table of monotonically increasing deflections versus forces. If the
direction block selects the spline stiffness formulation for a given direction, for
example FZ, then the property file should contain a corresponding spline stiffness
block for that direction, such as `[SPLINE_STIFFNESS_FZ]`

.

The following table shows the parameters stored in spline stiffness blocks.

Parameter | Type | Dimension FX, FY, FZ | Dimension TX, TY, TZ |
---|---|---|---|

Displacement | real | [L] | [A] |

Force | real | [F] | [F][L] |

When the property file is read the deflection and force values are converted from the units of the property file to the units of the solver model.

```
$---------------------------------------------------------- SPLINE_STIFFNESS_FY
[SPLINE_STIFFNESS_FY]
(SPLINE_DATA)
{ disp force }
-4.48 -1538.03776
-3.93 -933.55971
-3.38 -506.77016
-2.83 -227.72161
-2.28 -66.46656
-1.73 6.94249
-1.18 22.45304
-0.63 10.01259
-0.09 -0.43487
0.28 8.16256
0.83 66.78761
1.38 206.90616
1.93 458.46571
2.48 851.41376
3.03 1415.69781
3.58 2181.26536
4.47 3922.99269
```