Hi everyone, i have one query, how mode shapes can be drawn from a mode shape vector. Actually mode shape should comprise of a lot of points while i got just one point, its real and imaginary part; how could a mode shape can be generated from that ?

Hi everyone, i have one query, how mode shapes can be drawn from a mode shape vector. Actually mode shape should comprise of a lot of points while i got just one point, its real and imaginary part; how could a mode shape can be generated from that ?

[Image Analyst]

I have no idea until you attach your data in a .mat file, and attach some screenshots. Otherwise all I can say is to use the plot() function to plot either the real or the imaginary part. Clearly indicate what is a typical "mode shape" and what is the "mode shape vector" from which the "mode shapes" are supposed to be drawn from.

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

[Ayisha Nayyar]

Thanks a lot Image analyst for your guidance. Sorry for in convenience. Here's my code: f=f; fs=6400; mnum=5; for i=1:21; frf=b1(:,i); [fn,dr,ms]=modalfit(frf,f,fs,mnum,'Fitmethod','pp'); end

(where f is the frequency range starting from 1 to 2500Hz and fs= sampling frequency, frf is basically a FRF matrix of beam at 21 different points. frf=b1 and b1 is attached below.

and the part of answer showing modal shape vectors are displayed below:

0.00535814008085992 - 0.00535814008085992i 0.00348266401908543 + 0.00348266401908544i 0.000828406087890749 + 0.000828406087890727i 0.000406450088748395 + 0.000406450088748393i 0.000139194497984241 + 0.000139194497984201i

My question is that, whether they are correct mode shape vectors or not? if correct, how to draw mode shapes from them? Please help me out.

[Ayisha Nayyar]

Thanks a lot Image analyst for your guidance. Sorry for in convenience. Here's my code: f=f; fs=6400; mnum=5; for i=1:21; frf=b1(:,i); [fn,dr,ms]=modalfit(frf,f,fs,mnum,'Fitmethod','pp'); end

(where f is the frequency range starting from 1 to 2500Hz and fs= sampling frequency, frf is basically a FRF matrix of beam at 21 different points. frf=b1 and b1 is attached below.

and the part of answer showing modal shape vectors are displayed below:

0.00535814008085992 - 0.00535814008085992i 0.00348266401908543 + 0.00348266401908544i 0.000828406087890749 + 0.000828406087890727i 0.000406450088748395 + 0.000406450088748393i 0.000139194497984241 + 0.000139194497984201i

My question is that, whether they are correct mode shape vectors or not? if correct, how to draw mode shapes from them? Please help me out.

[Ayisha Nayyar]

Dear all, i am badly stuck in finding modal parameters from modalfit command. the problem is instead of a vector, o am getting just a single point as mode shape vectors. Please help me out.