Recent content by mkoijn9

Have a glance at this: http://mech.vub.ac.be/avrg/PhD/phd_parloo.pdf

Hi MikeyP, Heres the paper, where the author disputes the "time domain for low damping , freq domain for high damping" idea. At the end of page 92 (113 on the pdf page counter). http://mech.vub.ac.be/avrg/PhD/thesis_PV_web.pdf Also very good explaination of the lscf algorithm. Regards Albert

MikeyP, Thanks. In one of the papers from the developers of the polymax algorithm they prove that the idea that time domain is for light damped modes and frequency domain identification is for highly damped modes is not true. I don't think the polymax algorithm starts with impulse responses. All...

So I did rerun the tests and took GregLocks advice and only hit the bar 3 times, I did several measurements for each bar and took the best. It is surprisingly difficult to get good clean hits. The resulting frfs look very clean and coherence is also good. The new results are lower than before...

Thanks GregLocock, You may be right about Polymax, Lms aren't going to give me any help however as I wrote the software myself! I might just rerun the test to see if I get different results, This time I'll try 3 good hits instead of 10! Regards Albert

Thank you all for your replys, The bars were first excited under a loudspeaker and sprinkled with glitter to find the approximate position of the node lines of the first free/free bending mode, then the bars were suspended on the elastics at those positions. I excited the bars with a small...

Thanks ElectricPete, I did do a google search but didn't really find anything that explained it terms that I could understand! I will do some more searching. If anyone has a simple explanation tho. I would be very happy.

I am a little confused about damping. To try and understand it I took a bar of aluminium stock and cut two lengths, one twice as long as the other. I then suspended them on elastics and attached an accelorometer and excited the bars in turn with an impact hammer. After processing and curve...

My email is mkoijn9 at hotmail dot com

Hi, I've just written (in Fortran) an implementation of the Polymax modal analysis algorithm, and I was wondering if anyone has a set of multireference frf's (with the correct results also) I could use to test my algorithm to see if it is working correctly as I don't have access to any comercial...