Standing waves on arbitrary membrane

In summary, the conversation discusses the possibility of generating a fundamental mode of vibration by vibrating a stretched membrane over a closed loop of wire. The speaker's intuition suggests that there may be solutions to the 2D wave equation with a zero-displacement condition on an arbitrary closed boundary. However, they question whether this intuition is correct and why there may be fewer modes of vibration or wider frequency spacing for a complicated irregular boundary. The additional question considers the elasticity of a real membrane and the potential for multiple modes to quickly attenuate the membrane.
  • #1
the4thamigo_uk
47
0
My (probably misguided) intuition says the following :

'Take a closed loop of wire and bend it into any arbitrary shape so that it lies flat on a table. stretch a membrane over it (i.e. a soap membrane say). Then, I should be able to vibrate it at just the right frequency to generate (at least) a fundamental mode of vibration.'

In other words I think my intuition is telling me that there are solutions to the 2D wave equation with a zero-displacement condition on an arbitrary closed boundary.

Is my intuition right or wrong? If wrong, why?

Also, my intuition is telling me that for a complicated irregular boundary that there would be fewer modes of vibration or that they would be spaced more widely apart in terms of frequency.

Thanks

Andy

Additional:

If the intuition is incorrect, then is this something to do with the fact that a real world membrane is elastic and can stretch in ways that don't satisfy the wave equation?
 
Last edited:
Physics news on Phys.org
  • #2
I would think you'd generate several modes for different spatial scales that, in a real membrane, would quickly attenuate the whole membrane to the steady state as tey compete with each other.

A circle only has one spatial scale (the radius or diameter if you like), the arbitrary shape could have several.
 

FAQ: Standing waves on arbitrary membrane

1. What is a standing wave on an arbitrary membrane?

A standing wave on an arbitrary membrane is a type of wave that appears to be stationary or still in one place. It is created when two waves with the same frequency and amplitude traveling in opposite directions interfere with each other.

2. How are standing waves on arbitrary membranes studied?

Standing waves on arbitrary membranes are typically studied using mathematical models and simulations. These models take into account factors such as the material and shape of the membrane, as well as the properties of the waves traveling on it.

3. What is the significance of studying standing waves on arbitrary membranes?

Studying standing waves on arbitrary membranes can provide insight into the behavior of waves in different materials and structures. It can also help in the design and optimization of various devices, such as musical instruments, speakers, and sensors.

4. How are standing waves on arbitrary membranes different from other types of waves?

Unlike other types of waves, standing waves on arbitrary membranes do not transfer energy from one point to another. Instead, they oscillate back and forth in a fixed location. Additionally, the amplitude of a standing wave is determined by the boundary conditions of the membrane, rather than the energy of the wave.

5. Can standing waves on arbitrary membranes be observed in real-life situations?

Yes, standing waves on arbitrary membranes can be observed in various real-life situations. For example, they can be seen on the surface of a drum head when it is struck with a drumstick, or in the vibrations of a guitar string. They are also present in many natural phenomena, such as earthquake waves and ocean waves.

Similar threads

Back
Top