Vibration absorbers
Vibration absorbers
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Vibration absorbers


26th January 2023


Focus on vibration absorbers


Thanks to various projects, PYTHEAS Technology has gathered unique skills and knowledge on vibration control. Our website page dedicated to vibration control describes this subject and you will find in this article more information about vibration absorbers and PYTHEAS Technology’s resonators.


First of all, let’s dive into the fundamentals of vibration control.

Vibration absorbers
Vibration absorbers

Why and how can we eliminate vibrations from a structure?

Every structure has normal modes. This means that when it is excited at some specific frequencies, which are called natural frequencies, resonance frequencies or eigenfrequencies, the structure responds with a large vibration amplitude. Each structure has an infinity of normal modes and vibration control usually focuses on the first ones, at the lowest frequencies, which cause important displacements.

We can observe the resonance phenomenon on the graph opposite, where the oscillation amplitude is increased in the vicinity of a specific frequency.

The maximum of the oscillation amplitude, in black, is represented as a function of the excitation frequency. We can see that we have a peak indicating it is the resonance frequency.

The goal of vibration control is to limit the effect of this resonance frequency to restrict the movement of the structure under study. To achieve this goal, we can a vibration absorber to control the structure by harvesting and dissipating the vibrational energy.

Vibration absorbers
Vibration absorbers

What is a vibration absorber?

This peripheral device can be mounted on a structure and is designed to absorb and disperse the vibrational energy, which could result in significant oscillations of the structure.

There are different applications and objectives motivating the use of such absorbers:

  • Avoid structural damages. Let’s take the example of a satellite antenna, which is brittle. During the satellite movement, the antenna could be damaged or broken because of vibrations. To prevent it, a vibration absorber can be implemented to control the antenna and ensure its stability.
  • Users’ comfort improvement. Absorbers can be employed to reduce the passengers discomfort due to vibrations in trains or similar applications.
  • Noise reduction. Limiting vibrations leads to reducing the induced noise.

How does a vibration absorber work?

The use of a Tuned Mass Damper (TMD), or harmonic absorber, is quite common due to its simplicity of design and use. We can simplify the TMD’s representation as a counter-mass mounted on a spring-damper.

When the TMD is used at the frequency it has been designed for, it will oscillate and dissipate a portion of the energy causing the structure’s resonance. We can see on the graph opposite that the structure’s vibration (in blue) is reduced.

Using a TMD limits the structure’s displacement amplitude.

Vibration absorbers
Vibration absorbers

What are the distinctive features of PYTHEAS Technology’s vibration absorbers?

Piezoelectricity is in PYTHEAS Technology’s DNA. Among other innovative devices, we have developed piezoelectric vibration absorbers, also called piezoelectric resonators.

Adding piezoelectric elements, piezoceramics or patches of different sizes and shapes, allows an electromechanical energy conversion to happen. The piezoelectric element can convert part of the vibration’s mechanical energy into electrical energy. An electronic circuit, called “shunt”, is connected to the piezoelectric element to collect and disperse the extracted electric energy.

Piezoelectric resonators present better performances than usual TMDs with similar added mass (purple curve). This performance improvement is due to the electromechanical energy conversion and the shunt used to dissipate the vibration energy.

Coupling the piezoelectric element with « smart » electronics can provide attractive properties. For instance, the resonant frequency of the absorber can be adjusted to follow evolutions of the structure or several frequencies can be processed with a unique device.

The use of piezoelectricity presents another advantage: in addition to dissipating and reducing parasitic vibrations, piezoelectric resonators can be used to develop energy harvesting solution. Instead of dissipating the electrical energy generated by the piezoelectric materials, we can harvest part of this electricity, which can be stored and exploited.

Vibration absorbers
Vibration absorbers
Hopefully, this article answered your curiosity about vibration control and piezoelectric resonators. We remain at your disposal to discuss this subject together or to talk about your needs. For the most curious of you, stay tuned, we will soon communicate about Floriane’s thesis about “Robust piezoelectric resonators: application to low-frequency vibration reduction and energy harvesting”.