Surface protection in bio-shields via a functional soft skin layer: Lessons from the turtle shell.
J Mech Behav Biomed Mater
; 73: 68-75, 2017 09.
Article
en En
| MEDLINE
| ID: mdl-28162940
ABSTRACT
The turtle shell is a functional bio-shielding element, which has evolved naturally to provide protection against predator attacks that involve biting and clawing. The near-surface architecture of the turtle shell includes a soft bi-layer skin coating - rather than a hard exterior - which functions as a first line of defense against surface damage. This architecture represents a novel type of bio-shielding configuration, namely, an inverse structural-mechanical design, rather than the hard-coated bio-shielding elements identified so far. In the current study, we used experimentally based structural modeling and FE simulations to analyze the mechanical significance of this unconventional protection architecture in terms of resistance to surface damage upon extensive indentations. We found that the functional bi-layer skin of the turtle shell, which provides graded (soft-softer-hard) mechanical characteristics to the bio-shield exterior, serves as a bumper-buffer mechanism. This material-level adaptation protects the inner core from the highly localized indentation loads via stress delocalization and extensive near-surface plasticity. The newly revealed functional bi-layer coating architecture can potentially be adapted, using synthetic materials, to considerably enhance the surface load-bearing capabilities of various engineering configurations.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Piel
/
Tortugas
/
Exoesqueleto
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
J Mech Behav Biomed Mater
Asunto de la revista:
ENGENHARIA BIOMEDICA
Año:
2017
Tipo del documento:
Article
País de afiliación:
Israel