# Local Displacement

Ndumiso
Member

Hi

I want to evaluate the arrow displacement relative to its longitudinal axis. Could you please assist with this?

Please refer to the figure attached for visualization.

Tagged:

Ndumiso
Member

Hi

I want to evaluate the arrow displacement relative to its longitudinal axis. Could you please assist with this?

Please refer to the figure attached for visualization.

Tagged:

## Comments

Not sure what displacement you are trying to calculate. FYI, user-defined results can be used to calculate the customized results.

Below is the example to calculate total displacement from 3 displacement components.

Hi @cxquan

Thank you for answering.

I'm sorry, I am looking for the local displacement.

@Ndumiso

Strain is a measure of local displacement at the element level.

I see you are plotting Z axis displacement, which is much smaller than the X displacement.

I don't understand what you are looking for.

Hi @peteroznewman

I am looking for the dynamic spine of an arrow which is the maximum lateral displacement of the arrow. I hope that is clear now.

@Ndumiso Isn't that exactly what you plotted in the Directional Displacement for Z axis? What don't you like about that result?

Plotting would be simpler if you modeled the arrow spine with beam elements. Then there would just be a single row of nodes along the spine.

Do you need to construct a best fit line through the spine and plot lateral displacements from the best fit line? That could give you a slightly different result than the simple Directional Displacement in Z.

@peteroznewman

The presented displacement is calculated relative to the global coordinate system. The lateral displacement should be calculated from longitudinal axis of the arrow.

I think using a best fit line and calculating from there could work, however, I'm not sure how to do it. And I hope using the best fit line is different from using the path because I've tried using it but it didn't work.

@Ndumiso

Build a model using beam elements along the spine of the arrow. That will make it easy to export the nodal coordinates and deformations at a specific time, then outside ANSYS, using other software such as matlab or Excel, put a best fit line through those nodes to compute the lateral displacement of each node from the best fit line.

It may be possible to keep solid elements if the arrow spine was sliced into 1/4 circle segments so that a row of nodes ran down the center of the spine. The nodes on the centerline could be a Named Selection of nodes that could be exported without needing to use Beam elements.

@peteroznewman

Will try that. Thank you.