Damping behavior investigation and optimization of the structural layout of load-bearing biological materials

- Different staggered patterns of the biocomposites show different energy loss levels
- Nature designs biostructures with optimal feature sizes leading to high energy loss
- Stairwise architecture shows an extreme capacity of dissipating the dynamic energy
- Ability of shielding dynamic impact exists in biomaterials for protection function

Load-bearing biological materials, such as bone and nacre, exhibit superior mechanical properties to support and/or protect biological functionalities. To achieve this, an important ability of such materials is to effectively shield external dynamic impacts. The damping behavior of the biological materials mostly stems from their architecture and also the organic portion which intrinsically shows viscoelastic-plastic behavior. The loss modulus, a crucial representative of dynamic behavior, is a key index on how strong the bio-composite is able to damp the dynamic energy within its structure. This work aims to study the damping behavior of mostly seen staggered architectures of biological materials such as regular, offset, stairwise, herringbone and random staggering patterns to highlight the optimal layout, geometry, and feature sizes of the bio-composite in which the energy dissipation within the structure is maximal. Our studies show that not only the stairwise staggering arrangement overall offers the highest loss modulus amongst other existing architectures but also the aspect ratio of the platelet leading to the maximum loss modulus is remarkably in excellent agreement with experimental observations which might explain why this kind of arrangements is extensively observed in nature. Our findings here not only gain valuable insights into the dynamic behavior of load-bearing biological materials, but also provide useful guidelines to the design of bio-inspired engineering materials.

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