[SY-D4] Effect of friction and ductility on relaxation dynamics and mechanical memory of crumpled materials
Crumpled structures are ubiquitous in nature and technology. They combine low-density structures with surprising mechanical strength and the
ability to absorb mechanical energy. This combination of properties opens doors
to use them as mechanical metamaterials for a variety of applications.
However, in order to rationally design metamaterials, a thorough physical understanding of their unique features is needed. One remarkable physical property observed in crumpled structures is their slow mechanical relaxation
and their ability to carry a long lasting memory of previous mechanical states.
We experimentally investigate the role of material properties (ductility and friction) on relaxation dynamics of crumpled sheets by
comparing relaxation curves of different materials. We show that relaxation rates are not only dependent on material’s elastoplastic properties, but also rely on friction and adhesion between surfaces.This is further explored by using a two-step compaction protocol, that allowed us to probe deeper into the material’s relaxation behavior. We study the material dependency of the non-monotonic aging in a crumpled ball.
We show the normalized height of the non-monotonic aging peak depends
linearly on the time at which it arose with a slope that revealed a material property that
seemed to be correlated with the material dependent relaxation constant.
ability to absorb mechanical energy. This combination of properties opens doors
to use them as mechanical metamaterials for a variety of applications.
However, in order to rationally design metamaterials, a thorough physical understanding of their unique features is needed. One remarkable physical property observed in crumpled structures is their slow mechanical relaxation
and their ability to carry a long lasting memory of previous mechanical states.
We experimentally investigate the role of material properties (ductility and friction) on relaxation dynamics of crumpled sheets by
comparing relaxation curves of different materials. We show that relaxation rates are not only dependent on material’s elastoplastic properties, but also rely on friction and adhesion between surfaces.This is further explored by using a two-step compaction protocol, that allowed us to probe deeper into the material’s relaxation behavior. We study the material dependency of the non-monotonic aging in a crumpled ball.
We show the normalized height of the non-monotonic aging peak depends
linearly on the time at which it arose with a slope that revealed a material property that
seemed to be correlated with the material dependent relaxation constant.