[aop]

I would like to measure the acceleration caused by a known vibration pattern from different points in my geometry.

The vibration pattern is a frequency sweep (~100-2000 Hz) with constant force and I'd like to measure how it propagates through my geometry and what kind of acceleration does it causes in different points of the geometry.

I attached an picture of extremely gross simplification of the problem (actual geometry mesh has close to 1 million elements).

I wonder which of the ANSYS Analysis Systems would be the correct one for solving this problem?

[aop]

After some digging around the internet I ended up selecting Transient Structrural.

I have some trouble plotting my results. I have a sinusoidal force pulse which is 0,1 seconds long as an input to the system but when I try to plot any of the results they only have the result of the final step at 0,1 sec in the plot. I attached images of the input and output in this post.

When I animate the model is seems fine.

How do I make ansys plot between 0-0,1 sec like the input force is instead of starting from 0,1 sec?

[aop]

I figured out the problem, I had only 1 step in the simulation.

Now I have another issue. If I want to divide the simulation into let's say 100 separate time steps of equal length (for example 0.002 seconds each) is there easier way to do it than manually adjusting the end time of each time step as the software defaults to 1 second long time steps?

For example I start with just one time step of 0.002 seconds and then add 49 more the time steps will be 0.002, 1.0002, 2.0002, ... , 49.002 and I would like them to be like 0.002, 0.004, 0.006, ... 0,1. Currently I have manually change each and every time step which for 50 steps is pretty tedious.

[marowu]

Hi

In order to change the parameters of many steps at once, you have to enter analysis settings, than in a dialog named tabular data, all the steps should appear. You can select all of them and edit things like Initial substeps, Minimum substeps etc. For step end time: using MS Excel you can prepare necessary column of values, copy it and after selecting all the steps in tabular data, paste values from Excel.

Best regards,
Marek

[aop]

Originally Posted by marowu

Hi

In order to change the parameters of many steps at once, you have to enter analysis settings, than in a dialog named tabular data, all the steps should appear. You can select all of them and edit things like Initial substeps, Minimum substeps etc. For step end time: using MS Excel you can prepare necessary column of values, copy it and after selecting all the steps in tabular data, paste values from Excel.

Best regards,
Marek

Thanks!

I'm currently installing MATLAB so I can create the input force in tabular format instead of time dependant function so I may not have to play with manual time steps but I'm going to try the excel method too.

edit: Copy pasting tables from MATLAB seems to work great. Much easier to work with the frequency functions when it's easy to determine good sample rate so the "signal" doesn't get distorted.