Soil module#
Main command block - soil#
In this command block soil spring/damper forces can be attached to a main body. The formulation is performed so it can be used for other external distributed spring/damper systems than soil.
Sub command block – soil_element#
Command block that can be repeated as many times as needed. In this command block the distributed soil spring/damper system is set up for a given main body.
Obl. |
Command name |
Explanation |
|---|---|---|
* |
mbdy_name |
1. Main_body name to which the soil calculation points are linked. |
* |
datafile |
1. Filename incl. relative path to file containing soil spring properties (example ./soil/soildata.dat) |
* |
soilsections |
1. Distribution method: (“uniform” only possibility) |
2. Number of section (min. 2). |
||
damping_k_factor |
1. Rayleigh kind of damping. Factor the linear stiffness coefficients are multiplied with to obtain the damping coefficients. When the factor is 1.0 the vibration is critically damped for the rigid mainbody connected to the spring and dampers. |
|
\(\clubsuit\) |
set |
1. Set number in datafile that is used. |
*) Input commands that must be present
\(\clubsuit\)) Command can be repeated as many times as desired.
Data format of the soil spring datafile#
In the file (which is a text file) different distributed springs can be defined. Each set is located after the “#” sign followed by the set number. Within a set the following data needs to be present.
line 1 |
“spring type” |
(can be “axial”, “lateral” or “rotation_z”) |
|---|---|---|
line 2 |
“nrow ndefl” |
(nrow is number of rows, ndefl is number of deflections (colums) |
line 3.. 3+nrow |
“z_global F(1) F(2),…, F(ndefl)” |
First colum is the spring location (global z coordinate). The following colums are Force/length at the different deflection stations. First deflection must be zero. The forces are assumed symmetrical around the zero deflection. |
An example is given below:
This is a nonlinear soil spring demonstration file
#1
lateral (axial/lateral)
5 4 nrow ndefl
0.0 0.1 0.2 1.0 x1 x2 x3 ..... [m]
0.0 0 15 20 500 Z_G F_1 F_2 F_3 .... F_ndefl [kN/m]
10.0 0 15 20 500
20.0 0 15 20 500
30.0 0 15 20 500
40.0 0 15 20 500
#2
axial (axial/lateral)
5 4 nrow ndefl
0.0 0.1 0.2 1.0 x1 x2 x3 ..... [m]
0.0 0 150 200 5000 Z_G F_1 F_2 F_3 .... F_ndefl [kN/m]
10.0 0 150 200 5000
20.0 0 150 200 5000
30.0 0 150 200 5000
40.0 0 150 200 5000
#3
rotation_z (axial/lateral/rotation_z)
5 4 nrow ndefl
0.0 0.1 0.2 1.0 x1 x2 x3 ..... [rad]
0.0 0 150 200 5000 Z_G M_1 M_2 M_3 .... M_ndefl [kNm/m]
10.0 0 150 200 5000
20.0 0 150 200 5000
30.0 0 150 200 5000
40.0 0 150 200 5000