Periodic Reporting for period 1 - MetaVib (Lightweight Vibration Absorption using Buckling Metamaterials)
Okres sprawozdawczy: 2024-01-01 do 2025-06-30
Vibrations cause unwanted noise and even failure in many areas, including vehicles such as spacecrafts, road vehicles and trains,
sensitive optical or high-tech instruments and machinery. The market size for global vibration control systems was valued at 4.7
billion dollars in 2021 and is expected to expand to 8.1 billion dollars in 20302. This increase in demand is driven by a growing
emphasis on the mechanical stability and balancing of industrial machines, which require ever growing precision and vehicles, which
require ever growing safety.
To counter these vibrations, many strategies have been developed. One of the easiest ways is to use viscoelastic materials, but there is
typically an inherent trade-off: high dissipation entails low stiffness, whereas many applications typically require both high dissipation
and high specific stiffness. Another approach is to use active vibration damping, but these systems typically add an additional layer of
complexity and weight.
Here, we propose to use Euler buckling as a functional mechanism to create vibrations absorbers. Buckling structures are
simultaneously stiff and highly dissipative thanks to their high stiffness prior to buckling and highly nonlinear force and damping
response during post-buckling. To this end, we will use flexible mechanical metamaterials made of metal and fibre-reinforced
composites with tailored buckling and post-buckling. We will establish such metamaterials as a prime avenue to create lightweight
structures that is orders of magnitude more dissipative than their linear viscoelastic counterparts. We will hence establish their
potential as a competitive solution for lightweight structures combining high damping and high specific stiffness in high-tech and
aerospace applications. In particular, our metamaterials will allow to reduce the weight and increase the damping of energyabsorbing
components in vehicles, hence reducing their overall weight.
sensitive optical or high-tech instruments and machinery. The market size for global vibration control systems was valued at 4.7
billion dollars in 2021 and is expected to expand to 8.1 billion dollars in 20302. This increase in demand is driven by a growing
emphasis on the mechanical stability and balancing of industrial machines, which require ever growing precision and vehicles, which
require ever growing safety.
To counter these vibrations, many strategies have been developed. One of the easiest ways is to use viscoelastic materials, but there is
typically an inherent trade-off: high dissipation entails low stiffness, whereas many applications typically require both high dissipation
and high specific stiffness. Another approach is to use active vibration damping, but these systems typically add an additional layer of
complexity and weight.
Here, we propose to use Euler buckling as a functional mechanism to create vibrations absorbers. Buckling structures are
simultaneously stiff and highly dissipative thanks to their high stiffness prior to buckling and highly nonlinear force and damping
response during post-buckling. To this end, we will use flexible mechanical metamaterials made of metal and fibre-reinforced
composites with tailored buckling and post-buckling. We will establish such metamaterials as a prime avenue to create lightweight
structures that is orders of magnitude more dissipative than their linear viscoelastic counterparts. We will hence establish their
potential as a competitive solution for lightweight structures combining high damping and high specific stiffness in high-tech and
aerospace applications. In particular, our metamaterials will allow to reduce the weight and increase the damping of energyabsorbing
components in vehicles, hence reducing their overall weight.
We have explored the fatigue behaviour of metamaterials that buckle and are subject to cyclic loads, both using experiments and numerical simulations.
Since plasticity seems to be a dominant effect, we have performed many experiments to capture the buckling in the presence of plasticity and we have uncovered many interesting phenomena:
* an interesting form of domain wall propagation that seems intimately linked to plasticity
* an interesting form of "unbuckling" where an initially slender structure buckles and then unbuckles under compression.
* an interesting form of anti-Baushinger effect, where the structure plastic onset increases once it has undergone a compression/decompression cycle.
To complement these experimental and numerical findings, we also have started to construct a theoretical model that attempt to capture the propagation of domain wall when they buckle.
In addition to these results that were targeted at better understanding fatigue behaviour, we also have started to explore the behaviour of metamaterials under seismic load, in order to assess their performance in earthquake protection.
Since plasticity seems to be a dominant effect, we have performed many experiments to capture the buckling in the presence of plasticity and we have uncovered many interesting phenomena:
* an interesting form of domain wall propagation that seems intimately linked to plasticity
* an interesting form of "unbuckling" where an initially slender structure buckles and then unbuckles under compression.
* an interesting form of anti-Baushinger effect, where the structure plastic onset increases once it has undergone a compression/decompression cycle.
To complement these experimental and numerical findings, we also have started to construct a theoretical model that attempt to capture the propagation of domain wall when they buckle.
In addition to these results that were targeted at better understanding fatigue behaviour, we also have started to explore the behaviour of metamaterials under seismic load, in order to assess their performance in earthquake protection.
All the results described above exceed the state of the art. These results could educate the use of buckling metamaterials in vibration damping applications (e.g. for vehicles, industrial microscopes, and seismic protection), but they also highlight the need to better understand fatigue in these structures, which prior to our work was entirely unexplored.