Chladni Patterns on a Square Plate

When sand is sprinkled on a vibrating square plate and the plate is excited at one of its resonance frequencies, the sand collects at the "nodes" and forms pretty symmetric patterns

Category:

Howto & Style

Tags:

• chladni
• sound
• vibration
• standing
• waves

[yugenro]

While the visual is nice and interesting, I am really interested in the SOUND aspect... are these vibrations just out of human hearing range? Or is there some other reason for the silence?

[drdanku]

The reason for the silence is that I recorded this movie with an older digital camera that did not have a microphone. The range of frequencies for this particular set of patterns runs from about 100 Hz to about 5,000 Hz.

[apeek7]

Have you considered real time, stroboscopic holographic interferometry? I performed it both with a round plate and with a violin... You will get not only visual amplitude information but also visual phase information...

[drdanku]

yes - used holographic interferometry quite a bit while in grad school to look at guitars, snare drums, wine glasses, etc. More recently, we've used it to explore the vibration of golf club heads, car doors, automobile transmissions, as well as more musical instruments.

[apeek7]

I am not referring to time average interferometry or double exposure interferometry but real time, stroboscopic, holographic interferometry? The fringes slowly move if the strobe frequency is a hertz or two different from the vibration frequency

[drdanku]

Yup - we've done that also. But, unfortunately don't have any recent video. I think I have some older video of real time stroboscopic holographic interferometry of a standing sound wave in a rectangular waveguide. I'll have to see if I can convert it from vhs to digital and post it.

[salmarrr]

when i watch this, i imagine those shapes made in a crop fields. people or aliens who made those shapes, now could use a better, and easier method to create them! just to put some strong amplifier and play the music! hahahaha lol i donno! xD

[neglectoid]

fuk!!! that hurts my ears!!

[christine4xoxo]

do you put the plate right onto the speake?

[mariaealvarez]

@yugenro the video is just muted

[nikkkaforum]

please, could anyone tell me if i should put a plate DIRECTLY on the speaker?

[bunu230]

wher e can i buy the plates?