This article describes the workflow and settings/considerations for running ANSYS Platform on Nimbix - transferring large sets of data from excel using copy/paste commands in Nimbix (large data transfer not supported for certain data types).
We will walk through starting up the job, but if you are here just to see how to copy and paste tabular data, please skip to the STEPS FOR IMPORTING TABULAR DATA LOADS section.
To access ANSYS Platform on Nimbix platform, the following steps are required:
1. Select the desired ANSYS Platform release from the Compute dashboard
NOTE: If the option is not available in the first-page menu, press on “More” at the bottom of the page as shown in the image below:
2. A splash window will open. Select the ANSYS Workbench Platform option as shown below:
3. Cloud set-up screen opens and here you must choose some of your settings by clicking on the Tabs at the top of the window (General, Optional, etc) one tab at a time.
UNDER GENERAL TAB
1. Under Machine type when you click on the drop down caret on the right, you can select the type of machine you want to run your job on. The decision on machine type selection is based on size and complexity of your model and cost associated with the machine type (some machines will have higher RAM, others will only run the job on single CPU, others will have better graphics and therefore higher cost, etc).
NOTE: When running interactive based applications, you’ll find that selecting an NC9 or any NC* machine types should offer significant visual performance over not selecting an NC machine type. By selecting an NC machine, this places a GPU on your head-node, and offers better visual performance. Another thing to keep in mind is that when running interactively you can use a web-browser, or in some cases for large models or you might consider using RealVNC.
2. Select the number of cores:
The machine type you selected in the previous step, will dictate the increment in the number of cores that you can choose/select. For a very simple and small model, you can leave default selection, which in this case would be “16” or move the scroll bar to the desired number of cores or simply type over “16” the number of cores you wish to run your job on (we left it default in this case):
NOTE: Do not confuse number of cores with number of nodes (nodes represent the number of increment of cores that you selected. In the example above, 1 node represents 16 cores, 2 nodes correspond to 32 cores).
UNDER OPTIONAL TAB
1. Assign a JOB LABEL (give a name that will help you keep track on your running jobs. For example, MyPlatformProject):
Leave blank the wall time limit and the IP address. The Window size needs to be kept as default.
UNDER STORAGE TAB
1. Select vault type: Default vault is “Elastic_File"
The “Elastic_File” vault is recommended for small to medium size jobs, such as Icepak projects, simple linear Mechanical Analysis projects, some HFSS and simple Fluent projects (not multi-phase). For any complex and computationally heavy jobs, and where partitioning the job over number of cores becomes challenging, the Performance_SSD vault is strongly recommended. The Performance_SSD vault can be found in the drop-down under “Select Vault” tab (NOTE: requires subscription and extra monthly payment to have access to Performance_SSD vault).
Before submitting your job for running, you can preview your settings under the PREVIEW SUBMISSION tab.
2. You can start your job by clicking on the SUBMIT tab.
After ANSYS Workbench Platform has been successfully launched, you should be able to see the ANSYS Workbench in the preview and can access the window by clicking on it (you can see details on the number of nodes, some information regarding memory, etc):
After clicking “OK” on ANSYS feedback survey participation window, you are inside the Ansys Workbench environment:
ANSYS Workbench is a software environment for performing structural, thermal, and electromagnetic analyses. You can also perform tasks such as geometry creation and optimization, attaching an imported CAD geometry, setting up the finite element model, solving, and reviewing results.
Be sure to save this project by clicking on “File” “Save As” ChassisModalHarmonic (any name you wish to give; the name here is your file name, not be confused with the job name which is just a bookkeeping name of the project that runs, especially when you run multiple projects at once).
STEPS FOR IMPORTING TABULAR DATA LOADS
A constant value for the load (such as force, pressure, displacement) or a constant vector that gets decomposed in multiple directions is easy to handle in ANSYS Mechanical. However, there are situations, such as in Harmonic or Random Vibration analysis, or Acoustics Analysis, where your data consist of frequency dependent experimental readings (tabular data). Tabular loading allows the FEM analyst to use frequency/time dependent readings determined experimentally (direct measurement). In those cases, it is common to get large number of data readings, sometimes bigger than 10,000 rows of high-precision data. Therefore, manual input of the data is just simply not possible.
For certain type of load import, one can use External Data object available within Workbench interface. Simply drag and drop an External Data object onto the setup cell of your analysis. External Data tool can retrieve data from text files with space delimited, tabs, etc. You can find detailed documentation on how to import External Data and what type of data you can import, on Ansys Customer Portal or Learning Hub.
However, not all type of data import is supported within the External Data object. To import Tabular Data that is not supported by the External Data or if one wishes to just directly copy and paste the data from an Excel spreadsheet, one would need to use certain steps to perform this task on LINUX based NIMBIX platform.
For this example, we will refer to a project that performs a coupling analysis between Modal and Harmonic (not a mode superposition, but a decoupled Harmonic analysis following a simple Modal analysis) as shown below:
The steps to setup and perform both the modal and harmonic vibration analysis will not be shown in detail because it is not under the scope of the current article.
Here are the steps to follow:
1. Perform first your Modal Analysis (strongly recommended as most Harmonic analysis will require mode superposition or a better understanding of which frequencies to be aware of in order to avoid resonance.
2. Drag a Harmonic Analysis Tab and link it either at the Model level (as shown above) or at the Setup level (if mode superposition is desired)
3. After performing the Modal Analysis, perform Analysis settings and Load assignment under the harmonic Module as shown below:
4. Assign Settings under Analysis settings (such as Maximum Frequency Range, Solution Interval, how to store the data, frequency spacing, etc). This task is not relevant to this article and should be either known to the user or found on Ansys Customer Portal. For purposes of the example presented in this article, we limit our maximum frequency to 3000HZ, as shown below:
5. Assign harmonic load to the surface or surfaces that the part/component/assembly would be excited during the harmonic test setup.
For the purpose of showing a more complicated scenario, we will consider that the load/excitation is assigned to the printed circuit board that hosts all the electronics components and the load will be assigned in X, Y, Z direction as Tabular Data, as shown below:
NOTE: As you can see, the yellow color is an indication that no Tabular data has been assigned yet and the software is waiting for you to populate the Tabular Data Table with the appropriate frequency values and force load in all three directions: X, Y and Z.
The workaround to be able to import data directly from an Excel spreadsheet format, on NIMBIX LINUX, is the following:
1. Open https://sheets.google.com in a browser (please note that you will need to have an active Google account to have access to google sheets)
2. Start a “blank” new Excel spreadsheet
3. Here in the new Excel spreadsheet, copy and paste your data form your local machine Excel spreadsheet or go to File -> Import and browse for your data. For this article, we will copy and paste the data is saved on a local machine:
NOTE: We are only showing partially the data that has been copied from the local machine. However, the data shown above has 510 rows, each row and column containing data with high precision that need to be preserved and assigned as load in the Harmonic Tabular Data. Also, to be noted here, we did not copy the header of the Table but only the data; nonetheless, the first column represents frequency data in Hz and the next three columns represent force load in X, Y, Z directions and the unit for the load is Newton (be sure your data load unit matches the unit that you wish to assign the force/load in).
4. Assuming you have your project launched on Nimbix Cloud (as shown in the setup steps above), click on the “N” at the bottom left corner and launch “terminal emulator” as shown below:
5. In the Terminal Emulator window, type “firefox” and hit “Enter”
NOTE: “firefox” must be all lower case.
6. The Firefox browser will open, and you will need to type: https://sheets.google.com and login with your Google credentials. You should be able to find your data sheet in which you saved your data during the previous steps.
7. Select the spreadsheet you created in the previous steps described above (for the purpose of the example presented in this article, we called the Excel spreadsheet as “Frequency Data”.
8. Copy the data from the Excel spreadsheet (Ctrl+C) and Paste it in your Tabular data table in Ansys Mechanical.
NOTE: It is recommended to copy and paste one column at a time rather than selecting all columns at once.
Here is an image below, showing Tabular data is considered and the Force Tabular data input changed to color green in your Harmonic Response module:
9. Now your model is ready to Solve (if no other boundary conditions are wished to be added) and post process (stress/strain, acceleration frequency response for components of interest, etc)