Open result file, load condition 01

In the Analysis window, select Open for the load condition called dynamic_01.

If your analysis is not completed, or an error occur, you may load the equivalent file found in AquaSim\Demoes\CaseStudy02\Dynamic. In this folder, double click dynamic_01.avz, AquaView should be loaded.

Axial force in wire

You should observe how the axial force in the wire changes as the beam is lowered from air, through the water surface and below. From the top Toolbar menu in AquaView, select Result > Local section force > Axial force [N]. To get a better view of the lowering process, select Front from the top Toolbar menu.

To view the axial force in the connection point of the wire right click on the element as indicated in the figure above. Select Play from the playback area in the lower left corner.

Observe how the axial force is more or less constant as long as the beam is in air. When the beam crosses the water surface a significant drop in the axial force is seen. This is due to buoyancy in the beam and damping effects from the water. Buoyancy is a force acting in the opposite direction of gravity forces, causing the load in the wire to be reduced.

By selecting j from your keyboard, you will be provided with the maximum axial force in the components for the entire analysis. Which timestep the maximum axial force occur is also provided.

Open result file, load condition 02

Navigate back to the Analysis window and open the result file for load condition 02 by selecting Open next to dynamic_02.

Axial force in wire

To view axial force in the wire, select Result > Local section forces > Axial force [N]. Select the same element as in load condition 01 by right click on the element as indicated in the figure below.

Comparison results

You should now extract the results from the selected element in AquaView to a calculation program after your preferences. In this case study, we have chosen MS Excel.

In the Element result window for load condition dynamic_01.avz, select Copy all to clipboard , the Copy settings window will open.

Select Copy to clipboard. Open the calculation program and paste by selecting Ctrl + v.

Repeat this for the same element in dynamic_02.avz, paste the results in the calculation program next to the results from dynamic_01.avz.

Create a scatter plot of both result sets. Comparing axial forces between the two load conditions, it is seen that the magnitude is more or less similar. Before the beam cross the water surface, axial force is equivalent to gravitational forces of the system. When the beam crosses the water surface, the axial force drops to about 2.0E+05 N.

However, dynamic_01 has a more gradual decrease of axial force, and the drop occur at a later step than dynamic_02. This is due to the different wave periods in the load conditions. The wire is defined to winch out with a constant rate of speed. Since both load conditions are defined to be analyzed with the same number of analysis steps (Preincrement + Number total for waves = 5+ 80) the beam will pass the water surface at different analysis steps.

Dynamic considerations are now finished. Exit AquaView and AquaEdit.