Difference between revisions of "Modal Theorical FAQ"

Jump to navigation Jump to search

Modal Theorical FAQ (view source)

Revision as of 13:47, 17 July 2020

98 bytes removed ,  13:47, 17 July 2020
no edit summary
Line 1: Line 1:
[[File:modal.png|900px]]
[[File:modal.png|900px]]
==General
[https://orossas.sharepoint.com/:b:/g/support/ESHPvhJIsCBHijgwBeffvcABU-VZCt6ZON1OMcguK2sGoQ?e=qsLNUI What is modal analysis?.]<br>
[https://orossas.sharepoint.com/:b:/g/support/ETV5oBwxLjFHnsfVSL1hit0Bigt_2FuSJIbVmoHjAMPNug?e=Kb0vHk Common mistakes.]


[https://orossas.sharepoint.com/:b:/g/support/ESHPvhJIsCBHijgwBeffvcABU-VZCt6ZON1OMcguK2sGoQ?e=qsLNUI Could you explain modal analysis for me.]
==Windowing==
[https://orossas.sharepoint.com/:b:/g/support/ESeXYLSIKetIp7v1LyevBO0BI0hStYqFdzah5aO9kzgGIA?e=MTVQsF When impact testing, can the use of the exponential window cause any problems?]
[https://orossas.sharepoint.com/:b:/g/support/EUw3GiSkKIdBmFAZLE5vw-IBZ6-2-Yczz7zz4i3cTda2iQ?e=btozQG Which window is most appropriate for the various types of modal tests performed?]
[https://orossas.sharepoint.com/:b:/g/support/EZmiM-le4zpDvsyTb1Kfmc0B7AymLe5HB810BiQ2jtsxhQ?e=vJbs0G I heard someone say Pete doesn't do windows. Whets the scoop.]
==Acquisition==
==Acquisition==
[https://orossas.sharepoint.com/:b:/g/support/ERUU4dr0usxHiAn1Ih8FTAcBwQYcRPpNEMnUTsmT7JBCTg?e=Ag9Nit I ran one test with an x-excitation and can see some modes and another test with a  y-excitation and see some different modes could I use an oblique angle instead ?]<br>
===Generality===
[https://orossas.sharepoint.com/:b:/g/support/ESAbTQrm4yFKi0RMb2BVRTYBexWVHZewsr7hvDLPuEtUSQ?e=AZTle9 Is it really necessary to reject a double impact?]
[https://orossas.sharepoint.com/:b:/g/support/EQKjRyGlsShNg14lgX6gUtwBSq9W2VdBEwiDQ4jTvI8trg?e=1bCxCc basic steps to acquire data]
[https://orossas.sharepoint.com/:b:/g/support/Ee9ZZy7KqVxLjWURcjNtKSYBwxXFR_QjQVKhJofS9c4xKA?e=wdtfHO Do I need to have an accelerometer mounted in the X, Y and Z directions to do a modal test?]
[https://orossas.sharepoint.com/:b:/g/support/EVWdcqfwhc9Mshv8R6M5BKYB_I8x96uro6ItAhVah31wGA?e=qqb8So Is there a difference between a roving hammer and roving accelerometer test?]
[https://orossas.sharepoint.com/:b:/g/support/EVxxlCgPltJHslo8IlH2Y0wB5T_Z1Mn9mpXMiOhaIRWV8Q?e=h9dWZR Can the test setup have an effect on the measured modal data ? Do the setup boundary conditions and accelerometers have an effect?]
[https://orossas.sharepoint.com/:b:/g/support/EVxxlCgPltJHslo8IlH2Y0wB5T_Z1Mn9mpXMiOhaIRWV8Q?e=h9dWZR Can the test setup have an effect on the measured modal data ? Do the setup boundary conditions and accelerometers have an effect?]
[https://orossas.sharepoint.com/:b:/g/support/EfDJXZ2NsXBIpNnOPouoJLIBlqBNBjgTfnKQ4OUMay4R6g?e=igvjzh How many points are enough when running a modal test]
[https://orossas.sharepoint.com/:b:/g/support/EV4GFjhvcStErAqtxUDAFcUBU6db28UlUtckHR2l09Ad7A?e=3DHX1C is it better to collect averaged FRF data for a modal test? Or collect time data and process it afterwards?]
[https://orossas.sharepoint.com/:b:/g/support/EV4GFjhvcStErAqtxUDAFcUBU6db28UlUtckHR2l09Ad7A?e=3DHX1C is it better to collect averaged FRF data for a modal test? Or collect time data and process it afterwards?]
[https://orossas.sharepoint.com/:b:/g/support/EfDJXZ2NsXBIpNnOPouoJLIBlqBNBjgTfnKQ4OUMay4R6g?e=igvjzh How many points are enough when running a modal test]
[https://orossas.sharepoint.com/:b:/g/support/EZfWJLtRuCtDpCkrd09zwEUBz2GXFlFjmWmBjBPJ7O1igw?e=o5c75e We talked about the number of points needed for a modal test before.]
[https://orossas.sharepoint.com/:b:/g/support/EZfWJLtRuCtDpCkrd09zwEUBz2GXFlFjmWmBjBPJ7O1igw?e=o5c75e We talked about the number of points needed for a modal test before.]
[https://orossas.sharepoint.com/:b:/g/support/EV3I4RVyqhtInP82-HGjH2gBff6U72IhA7orXLTNWH5LLg?e=JGOeAo Is there any benefit to using multiple references?I thought only one reference was need.]
===Sensor and reference===
 
[https://orossas.sharepoint.com/:b:/g/support/EQKjRyGlsShNg14lgX6gUtwBSq9W2VdBEwiDQ4jTvI8trg?e=1bCxCc Could you please explain the basic steps to acquire data for modal test]


[https://orossas.sharepoint.com/:b:/g/support/ERUU4dr0usxHiAn1Ih8FTAcBwQYcRPpNEMnUTsmT7JBCTg?e=Ag9Nit I ran one test with an x-excitation and can see some modes and another test with a  y-excitation and see some different modes could I use an oblique angle instead ?]<br>
[https://orossas.sharepoint.com/:b:/g/support/Ee9ZZy7KqVxLjWURcjNtKSYBwxXFR_QjQVKhJofS9c4xKA?e=wdtfHO Do I need to have an accelerometer mounted in the X, Y and Z directions to do a modal test?]
[https://orossas.sharepoint.com/:b:/g/support/EVWdcqfwhc9Mshv8R6M5BKYB_I8x96uro6ItAhVah31wGA?e=qqb8So Is there a difference between a roving hammer and roving accelerometer test?]
[https://orossas.sharepoint.com/:b:/g/support/ET7xJmNNuyNGnpoX_E0s9MIB7BfU3wKfDjv3gtZlsjGGZA?e=M0mIrO Someone told me that you must have multiple references to identify pseudo repeated.]
[https://orossas.sharepoint.com/:b:/g/support/ET7xJmNNuyNGnpoX_E0s9MIB7BfU3wKfDjv3gtZlsjGGZA?e=M0mIrO Someone told me that you must have multiple references to identify pseudo repeated.]
 
[https://orossas.sharepoint.com/:b:/g/support/EV3I4RVyqhtInP82-HGjH2gBff6U72IhA7orXLTNWH5LLg?e=JGOeAo Is there any benefit to using multiple references?I thought only one reference was need.]
[https://orossas.sharepoint.com/:b:/g/support/ESRlQH3hGgpLgqwRbYFMOHQBb-J3fkac76JMhSCwgAF_pg?e=qQRnZL Should I always use a hard tip for impact testing . . .so the input spectrum is flat over all frequencies]
[https://orossas.sharepoint.com/:b:/g/support/ESRlQH3hGgpLgqwRbYFMOHQBb-J3fkac76JMhSCwgAF_pg?e=qQRnZL Should I always use a hard tip for impact testing . . .so the input spectrum is flat over all frequencies]
Other
[https://orossas.sharepoint.com/:b:/g/support/ESAbTQrm4yFKi0RMb2BVRTYBexWVHZewsr7hvDLPuEtUSQ?e=AZTle9 double impact question]
==Shacker==
==Shacker==
[https://orossas.sharepoint.com/:b:/g/support/EZ0xK6BALQlMgiXqGEh1UNkBJfsAo4aPmTwE7UKcLSppEg?e=NpNUPs Is there any difference between a modal test with a shaker excitation or impact excitation?]
[https://orossas.sharepoint.com/:b:/g/support/EZ0xK6BALQlMgiXqGEh1UNkBJfsAo4aPmTwE7UKcLSppEg?e=NpNUPs Is there any difference between a modal test with a shaker excitation or impact excitation?]
Line 32: Line 30:
[https://orossas.sharepoint.com/:b:/g/support/EWVXgK-KbPBLn3VMLviBuuQB7XgfOpaAPUzLPe0dbMhe9A?e=AVixDw I showed some mode shapes to someone. They asked me if the structural design was ok. What should I tell them ?]
[https://orossas.sharepoint.com/:b:/g/support/EWVXgK-KbPBLn3VMLviBuuQB7XgfOpaAPUzLPe0dbMhe9A?e=AVixDw I showed some mode shapes to someone. They asked me if the structural design was ok. What should I tell them ?]
==Modal theorical==
==Modal theorical==
===Windowing===
[https://orossas.sharepoint.com/:b:/g/support/ESeXYLSIKetIp7v1LyevBO0BI0hStYqFdzah5aO9kzgGIA?e=MTVQsF When impact testing, can the use of the exponential window cause any problems?]
[https://orossas.sharepoint.com/:b:/g/support/EUw3GiSkKIdBmFAZLE5vw-IBZ6-2-Yczz7zz4i3cTda2iQ?e=btozQG Which window is most appropriate for the various types of modal tests performed?]
[https://orossas.sharepoint.com/:b:/g/support/EZmiM-le4zpDvsyTb1Kfmc0B7AymLe5HB810BiQ2jtsxhQ?e=vJbs0G I heard someone say Pete doesn't do windows. Whets the scoop.]
===Curvfitting===
===Curvfitting===
[https://orossas.sharepoint.com/:b:/g/support/EeYfWtoUNHhIgpr2i1_wYkcBZPq3GmF0ETi7I8DtsuWKoQ?e=d5nXIx Curvefitting is so confusing to me!]
[https://orossas.sharepoint.com/:b:/g/support/EeYfWtoUNHhIgpr2i1_wYkcBZPq3GmF0ETi7I8DtsuWKoQ?e=d5nXIx Curvefitting is so confusing to me!]
Line 64: Line 66:




[https://orossas.sharepoint.com/:b:/g/support/ETV5oBwxLjFHnsfVSL1hit0Bigt_2FuSJIbVmoHjAMPNug?e=Kb0vHk What are some of the major mistakes people make in modal tests so I don't make the same one]
 


[https://orossas.sharepoint.com/:b:/g/support/EX4IEP3GWoRPr1V5RTGD5jcBiHNsJ0rJPWpdPaJ_bH_aaQ?e=LIqzlD Why do some measurements have anti-resonances and others not ?]
[https://orossas.sharepoint.com/:b:/g/support/EX4IEP3GWoRPr1V5RTGD5jcBiHNsJ0rJPWpdPaJ_bH_aaQ?e=LIqzlD Why do some measurements have anti-resonances and others not ?]
Retrieved from "https://wiki.oros.com/index.php?title=Special:MobileDiff/7044"

Navigation menu