INTERPOLATE GRAPHIC DISPLACEMENT

[cobayatron]

Hi Guys,

I'm aiming to produce a tool that helps me visualize the mode shapes of a wing but I'm struggling to plot the results. A little of context:

- I have a wing with several accelerometers on it. I'll perform a modal analysis (impact test) an I'll have time signals which I will convert to frequency (Frequency Response Function) and then I'll keep the peak values and the sign of the imaginary plot. That will give me the direction of the movement with respect to each other.

The idea is then to, having the exact location of the accelerometers, plot that displacement (with sign) in the 3D plot where I previously defined a mesh. (VI attached) I think I can handle up to this point. My problem appears if I want to interpolate the displacement so that nodes close to an accelerometer  moves proportionally to its distance to the accelerometer. Thanks!

[LocalDSP]

Hi 

Could you eventually save sample data on your VI front panel and re-post it?

[Riley_Ilieva]

Hi Cobayatron, 

Thank you for attaching the VI. I am not sure I understand what your question is. Could you point us in the direction of the part of the code that you are referring to? Is this related to the calculation of the input to the 3D graph or a property of the graph? 

Kind Regards, 

Riley Ilieva

Applications Engineer

National Instruments

[cobayatron]

Hi,

Thanks for your messages.

Sorry I wasn't too clear. I've been adding some other things to the VI (attached), this is in fact (or will be a subvi) where the location of the accelerometers (X,Y defined in the wing plane) and the peak deformation will be inputs. I've added the interpolation property node but I'm unsure this does what I'm expecting. Does it lineally interpolate the values on the surface??? Thanks!

[cobayatron]

Hi,

Thanks for your messages.

Sorry I wasn't too clear. I've been adding some other things to the VI (attached), this is in fact (or will be a subvi) where the location of the accelerometers (X,Y defined in the wing plane) and the peak deformation will be inputs. I've added the interpolation property node but I'm unsure this does what I'm expecting. Does it lineally interpolate the values on the surface??? Thanks!

[cobayatron]

Sorry for posting twice the same message.

I've been working a little on this, I thought I had it when I found the interpolate function, however I don't really understand the plot. I impose the deflections in the nodes close to the accelerometers' location. Since the wing is in a cantilever configuration, I also impose 0 deflection in the nodes at x=0. The problem with the plot is that it does not respect these conditions. What am I missing here?

[cobayatron]

Latest VI option

[Riley_Ilieva]

Hi, 

Thank you for sending this but this looks like a different application and has no graph in it. Could you possibly specify why the function is not working? Is it the result that is generated from a function or the calculation following a function? Are you talking about the ramp pattern function or the property node on the 3D graph or is there an interpolation function somewhere in the VI? 

Many Thanks, 

Riley Ilieva

Applications Engineer

National Instruments

[cobayatron]

You're right, that's another vi I had...sorry, I'm working in many things at the same time hehehehehe.

If you check the 3D graph, the x=0 nodes should be at z=0, that's what I'm trying to impose before the interpolation function  and then when I interpolate I was hoping that the in the nodes where I previously imposed a deflection (z value) that would be respected.

[Riley_Ilieva]

Hi, 

Thank you for the info but could you elaborate a bit more, we don't understand what results you are expecting and what is wrong with the function or results. 

Many Thanks, 

Riley