Calculate Bell Ringing Frequency | 8.5cm Diam, Cast Brass

In summary, you would need to measure the frequency of the bell, find the dominant strike chord, and get a piezo alarm that can ring at that frequency.
  • #1
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How do I calculate the frequency of an 8.5 cm diameter bell ?
The bell is cast brass for resonance, but I intend to activate it with a buzzer so sound will last for more than a few seconds. Does the weight affect anything other than volume ? I intend to use it inverted, supported near the "top".
 
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  • #2
You don't.
For a real bell you would need to use numericial methods to solve the equations (unless you have a VERY simple bell, i.e. something very symmetric) but even then you are not very likely to get a useful answer, partly because real bells are note made of a "perfect" material; various imperfections etc (which in turn depends on how the bell was cast) can have quite a large influence on the resonance frequency.

Is there any reason why you simply can't measure the frequency? It should be easy, all you need is a microphone connected to the sound card of a computer+some suitable software.
 
  • #3
Here is a description of what you have to do to http://www.rps.psu.edu/sep99/freedom.html".

"dividing the surface of the bell into a grid made of 450 squares. 'There's an equation describing the vibration of each square, and the computer can solve all the equations simultaneously,' "
 
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  • #4
"a traditional English-bell profile "
What I need is the "dominant strike chord"

Any suggestions on "some suitable software" ?
 
  • #5
Well, all you need is some software that can show you the frequency spectrum of the signal from the microphone. Sigview comes to mind and you can download a free trial version.

However, you could also try something VERY simple such as AP Tuner which is a program used to tune guitars, by default it will only show you what note you are playing (i.e. A, C# etc) but if you look n the "Recording Device and Calibration" it will also show you the last detected frequency.
Or, alternatively, you could just look up what frequency e.g. C# corresponds to (chances are that a bell will be reasonably well "tuned" to a note).
 
  • #7
I need piezo(?) alarms to ring my bell. I need a resonant frequencies of 392 hz and 1700 hz, 12 volts would be best. Also need a 30 minute timer.
 

1. How do you calculate the bell ringing frequency for an 8.5cm diameter, cast brass bell?

The formula for calculating bell ringing frequency is: Frequency = (1 / 2L) * (√T/ρ), where L is the length of the bell, T is the tensile strength of the material, and ρ is the density of the material. For an 8.5cm diameter, cast brass bell, this would be: Frequency = (1 / 2 * 8.5cm) * (√T/ρ).

2. What is the length of an 8.5cm diameter, cast brass bell?

The length of a bell is typically measured from the top of the bell to the bottom of the clapper. To get an accurate measurement, you can use a measuring tape or ruler and measure from the highest point of the bell to the lowest point, including the clapper.

3. How do you determine the tensile strength of a cast brass bell?

The tensile strength of a material can be found in its material properties or specifications. For cast brass, the tensile strength can range from 550-800 MPa. You can also consult with the manufacturer of the bell for more specific information.

4. What is the density of cast brass?

The density of cast brass can vary slightly depending on the exact composition of the brass alloy. However, on average, the density of cast brass is around 8.4 g/cm3.

5. How does the bell diameter affect the ringing frequency?

The diameter of a bell can affect its ringing frequency by changing the length of the bell and the surface area of the material. A larger diameter bell will typically have a lower frequency compared to a smaller diameter bell, assuming all other factors are constant.

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