A guy breaks glass with voice in this video, demonstrating the destructive nature of resonance.

Buy it here: Audit it. Improve it! Getting the Most from Your Vibration Program – by Alan Friedman.

Resonance is a condition that exists when a forcing frequency excites the natural frequency of a structure. In this case, the Derek’s voice is the forcing frequency and the wine glass is the structure. In  the video you will notice that Derek taps the glass and listens to the sound it makes. This is called a “bump test” and it is a common way to test for natural frequencies. Derek will then try to excite the natural frequency by singing at the same frequency.  This creates the condition called resonance.

When the glass is in resonance it vibrates a great deal causing the straw to move. This lets the Derek know that he is singing the right note. As you can see, it doesn’t take long for the glass to break, which is why resonance is a situation that should be avoided.

If you try this at home, be sure to wear safety glasses!

You can see the same thing in the video below, bit here a speaker and a signal generator are used to create the sound. You can see the mode shape of the glass when it is in resonance.

Resonance is a potentially destructive condition that needs to be remedied ASAP!

Buy it here: Audit it. Improve it! Getting the Most from Your Vibration Program – by Alan Friedman.