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Comparing FEA and experimental modes. Import data.




I have to make an MAC of modes from FEA and experimental alysis. The FEA was performed using MSC Patran/Nastran. Guys, do you have any manual how to import data from FEA into test.lab and than use it to perfom MAC?


Best Regards,



Re: Comparing FEA and experimental modes. Import data.

Siemens Legend Siemens Legend
Siemens Legend

Hi Rafal,

Can you export the file to Universal file format?  Test.Lab can read and import the data; once the data is imported to Test.Lab, then you can use Polymax to generate MAC.  If you're our customer on software maintmence support, please call test support at 1 800 955 0000 with your sold to ID, then option 2 and option 8 for Test.Lab support.  We would happy to help you out.



Re: Comparing FEA and experimental modes. Import data.

Thanks for reply. I'm not a customer. I am a student who need compare a result of normal modes experiment and FEM analysis, I'm using the academy computer.

During the experiment i have been using 20 sensors which provdies me data of displacement vectors of these sensors. From FEM analysis I recieved the same data but for nodes. Now I have to put the displacement vectors of nodes into test.lab. Do you know in which format it should be done? Is it any manual avilable that show me how to do that manually?

Re: Comparing FEA and experimental modes. Import data.

Siemens Phenom Siemens Phenom
Siemens Phenom



A couple of questions?

1)  Do you have access to the Nastran Data Driver license in LMS Test.Lab?  If so, we can read the Nastran modes from the *.pch or *.op2 Nastran results file with the Nastran Data Driver license turned on.  If not, you'll have to use the Universal File option that Hong suggests.

2)  Are the two geometries in the same space?  i.e. XYZ axes system and scale?  That would be a requirement unless you can easily rotate and scale one of the geometries.

3)  Are the node numbers the same between TEST and CAE \ FEA?   This is the full node name.  Since the FEA nodes will not have a geometry component name, the Test.Lab nodes would need to have no component as well.  If they don't have the same node names will will need to make it so.   


Correction:  The following will work for correcting data (FRF, Throughput, spectra, etc. but will not work for Mode shapes since we can not edit the Point ID's within a Mode.  You may be able to use the Alias Geometry feature that is new in LMS Test.Lab 17 to handle this problem for data other than Mode shapes.


Once those are setup, you can add the FEA modes to the Input basket and do a MAC between mode set A (the TEST modes) and mode set B (the FEA modes in the Input Basket).


Standard Correlation software like our LMS Virtual.Lab Correlation product and our Simcenter Correlation product would be able to handle the rotating and scaling of the geometries and also the different node numbers (and even different number of modes).  Since LMS Test.Lab is not correlation software, the nodes should be the same number, have the same name and be in the same space.

Re: Comparing FEA and experimental modes. Import data.

Siemens Valued Contributor Siemens Valued Contributor
Siemens Valued Contributor


Another option if you have the nastran data driver license "TL-DTP.12.2" you can import the .op2 directly into Test.Lab and perform the correlation according to  the steps:


1 - Enable the Add-in Modal Analysis and Nastran data driver in TL desktop.


2 -  Search your data> Right click > Replace in Input Basket


3 - In the Modal Validation Tab, select the modal analysis from test in the top

4 - Select to read the FEA data from input basket or from your project

5 - Select MAC 

6 - You can choose the type of visualization that you want: table/matrix/geometry...




If you do not have the nastran data driver license you can try other formats.

The faq 632 in our GTAC website show all formats supported in Test.Lab:


For further questions, please contact GTAC support.



Emerson Umbinger

Re: Comparing FEA and experimental modes. Import data.


Thank you all for advice. Unfortunalty I am not able to perform this calculation, even with your help. I decided to change the way of my calculation.


As you know I have to perform the MAC. Now what I want to do is to extract a value of vectors of displacements for each sensor.


What i have from Nastran .F06 file.


R E A L E I G E N V E C T O R N O . 1

9821 G 1.015167E-06 -4.864411E-06 -1.519196E-05 1.249779E-11 8.743192E-11 -1.749956E-09
9822 G 1.060670E-06 -4.864437E-06 -1.519163E-05 1.331622E-11 8.771227E-11 -1.749960E-09
9823 G 5.877554E-07 -4.865365E-06 -1.519518E-05 1.134383E-11 9.421307E-11 -1.751963E-09
9824 G 5.499529E-07 -4.865276E-06 -1.519546E-05 1.434522E-11 8.345703E-11 -1.749201E-09
9825 G 5.149390E-07 -4.865133E-06 -1.519571E-05 1.208602E-11 8.921269E-11 -1.750677E-09
9826 G 4.843663E-07 -4.864942E-06 -1.519593E-05 1.327825E-11 8.780527E-11 -1.747596E-09
9827 G 4.733168E-07 -4.864667E-06 -1.519599E-05 1.328709E-11 8.795326E-11 -1.754505E-09
9828 G 4.923774E-07 -4.864430E-06 -1.519584E-05 1.224031E-11 8.818981E-11 -1.746739E-09
9829 G 5.295367E-07 -4.864370E-06 -1.519556E-05 1.390191E-11 8.125470E-11 -1.752216E-09
9830 G 5.686912E-07 -4.864371E-06 -1.519527E-05 1.215336E-11 9.545373E-11 -1.745961E-09
9831 G 5.935608E-07 -4.865008E-06 -1.519512E-05 1.299683E-11 8.278279E-11 -1.743988E-09
9832 G 5.650230E-07 -4.864963E-06 -1.519533E-05 1.299392E-11 8.798048E-11 -1.749410E-09
9833 G 5.330309E-07 -4.864947E-06 -1.519557E-05 1.298675E-11 8.786303E-11 -1.752197E-09
9834 G 5.110381E-07 -4.864864E-06 -1.519573E-05 1.298755E-11 8.650115E-11 -1.750543E-09
9835 G 5.086965E-07 -4.864743E-06 -1.519574E-05 1.298370E-11 8.632199E-11 -1.746519E-09
9836 G 5.264679E-07 -4.864650E-06 -1.519560E-05 1.298324E-11 8.864485E-11 -1.750183E-09
9837 G 5.513070E-07 -4.864614E-06 -1.519541E-05 1.299258E-11 9.011496E-11 -1.751554E-09
9838 G 5.787468E-07 -4.864625E-06 -1.519521E-05 1.299428E-11 8.577378E-11 -1.756788E-09
9839 G 6.268177E-07 -5.565366E-06 -1.522993E-05 1.422896E-11 8.984389E-11 -1.753427E-09
9840 G 6.204948E-07 -5.565025E-06 -1.522996E-05 1.210846E-11 8.689367E-11 -1.741172E-09
9841 G 6.141718E-07 -5.564686E-06 -1.522999E-05 1.311480E-11 8.736515E-11 -1.759232E-09
9842 G 6.078488E-07 -5.564345E-06 -1.523002E-05 1.340138E-11 8.783752E-11 -1.745453E-09
9843 G 6.530973E-07 -5.564348E-06 -1.522969E-05 1.246882E-11 9.266045E-11 -1.752911E-09
9844 G 6.594823E-07 -5.564676E-06 -1.522966E-05 1.294006E-11 8.466274E-11 -1.742765E-09
9845 G 6.658003E-07 -5.565003E-06 -1.522962E-05 1.293897E-11 8.805699E-11 -1.757005E-09
9846 G 6.721621E-07 -5.565329E-06 -1.522959E-05 1.197056E-11 8.701954E-11 -1.747281E-09
9847 G 6.983488E-07 -5.564351E-06 -1.522935E-05 1.348449E-11 8.348879E-11 -1.748093E-09
9848 G 7.041893E-07 -5.564648E-06 -1.522932E-05 1.293311E-11 9.030957E-11 -1.754165E-09
9849 G 7.100602E-07 -5.564944E-06 -1.522930E-05 1.292978E-11 8.731935E-11 -1.745496E-09
9850 G 7.158683E-07 -5.565238E-06 -1.522927E-05 1.355062E-11 8.671407E-11 -1.751594E-09
9851 G 7.436018E-07 -5.564354E-06 -1.522902E-05 1.225169E-11 9.090483E-11 -1.750955E-09
9852 G 7.489047E-07 -5.564619E-06 -1.522899E-05 1.292871E-11 8.561516E-11 -1.747443E-09
9853 G 7.541640E-07 -5.564882E-06 -1.522897E-05 1.292732E-11 8.773848E-11 -1.752283E-09
9854 G 7.594368E-07 -5.565145E-06 -1.522894E-05 1.255773E-11 8.777522E-11 -1.748646E-09
9855 G 7.888557E-07 -5.564358E-06 -1.522868E-05 1.367893E-11 8.521506E-11 -1.749371E-09
9856 G 7.935472E-07 -5.564589E-06 -1.522866E-05 1.292658E-11 8.904687E-11 -1.751110E-09
9857 G 7.982457E-07 -5.564820E-06 -1.522864E-05 1.292661E-11 8.737407E-11 -1.748499E-09
9858 G 8.029163E-07 -5.565050E-06 -1.522861E-05 1.315427E-11 8.720399E-11 -1.750680E-09
9859 G 8.341083E-07 -5.564361E-06 -1.522835E-05 1.216831E-11 8.912605E-11 -1.750154E-09
9860 G 8.381865E-07 -5.564559E-06 -1.522833E-05 1.292642E-11 8.661355E-11 -1.749363E-09
9861 G 8.422448E-07 -5.564756E-06 -1.522831E-05 1.292664E-11 8.764527E-11 -1.750674E-09
9862 G 8.463011E-07 -5.564953E-06 -1.522829E-05 1.277258E-11 8.768047E-11 -1.749373E-09
9863 G 8.793604E-07 -5.564364E-06 -1.522802E-05 1.363130E-11 8.644348E-11 -1.749855E-09
9864 G 8.827761E-07 -5.564528E-06 -1.522800E-05 1.292681E-11 8.816778E-11 -1.750058E-09
9865 G 8.861876E-07 -5.564691E-06 -1.522798E-05 1.292661E-11 8.759424E-11 -1.749483E-09
9866 G 8.895832E-07 -5.564853E-06 -1.522796E-05 1.306700E-11 8.724903E-11 -1.750212E-09
9867 G 9.246170E-07 -5.564368E-06 -1.522768E-05 1.231008E-11 8.812532E-11 -1.749876E-09
9868 G 9.300330E-07 -5.564624E-06 -1.522765E-05 1.292809E-11 8.740333E-11 -1.750162E-09
9869 G 9.273319E-07 -5.564496E-06 -1.522767E-05 1.292793E-11 8.732622E-11 -1.749983E-09
9870 G 9.327250E-07 -5.564752E-06 -1.522764E-05 1.276659E-11 8.764943E-11 -1.749659E-09


Now I have to get this kinde of data from test.lab. Do you guys know how to extract it?

Re: Comparing FEA and experimental modes. Import data.

Siemens Phenom Siemens Phenom
Siemens Phenom



In LMS Test.Lab if you right click on a Mode shape in the Navigator or Modal Analysis to get it's properties and on one of the tabs will be the modal vector:  Node ID, Real, Imaginary and Amplitude, Phase.


Be careful you are comparing apples and apples though.  Are your mode shapes in LMS Test.Lab Real or Complex?  You can calculate both and make sure your FEA data is the same.


What is the mode scaling?  On Modal Validation we can scale the modes such that modal mass is 1, stiffness is 1, the largest value is 1, the vector is 1, etc.  Make sure you have the same scaling as your FEA data.


I expect your FEA data are Real Modes with Unity Modal Mass scaling.


If you wanted to try the MAC again in LMS Test.Lab, browse to the Nastran results and export the Geometry and Modes to Universal file while turning on the option  to Generate a Node map file.  This will create an ASCII file besides the Universal file with a *.map extension which you can edit.  It will have a column for the CAE node and a column for the TEST node.  Edit it to use the TEST nodes.  You can then browse back to the Universal file and when you either Copy it the project or Add it to the Input Basket it will have the TEST nodes and you can do a MAC between the Test modes and the FEA modes (with Test node names) on Modal Validation.   If you need help with this please reach out to your support team.  If you provide the FEA modes in a *.pch or *.op2 file and the Test.Lab project with your test nodes they can help.

Re: Comparing FEA and experimental modes. Import data.


The best way to campare the FEA and Test modal is to use the LMS Virtual Lab not the LMS TEST LAB.