Please open the excel sheet. To briefly explain you what's there in it, the column 1: sample points; column 2: time in seconds; column 3: strain gage values at 26in from one end of the simply supported beam; column 4,5....34: strain gage values at 66in,86in,....646in from one end of the simply supported beam, respectively. The attached vi file is used get the excel values to Labview and show the waveform chart. Open the vi, then give the file path to the excel sheet. In the start cluster control, put Column 2 and Row 620. In the end cluster column, put column 34 and Row 845. From the waveform chart, The values of each strain gage from the range of 6 to 8.5 seconds will be ploted in waveform chart. Now, I need to perform FFT with hanning window to each strain gage, then read the peak imaginary magnitudes of FFT, arrange them according to the beam distances (26in, 46in,....646in) and join those points to get the first mode shape.
Note:The waveform chart X-axis is showing the sample points instead of time in seconds.
The file FFT and Power spectrum units.vi has the information to perform FFT . The time domain signal is a cluster that is wired to the FFT but in my case (read excel values.vi), it is a 2D array of strain and time values.
Question1: How should I wire this 2D array to FFT (with all the cases listed in the case structure of FFT and power spectrum.vi) and get the peak values of each strain gage from FFT?
Question 2: How can I arrange those peak values according to the beam distances (26in, 46in,....646in)?
Question 3: How can I join those points to get the first mode shape?
