Composite design bioinspired by the mesocarp of Brazil nut (Bertholletia excelsa)

Author(s)

Sonego, M. ; Sciuti, V. F. ; Vargas, R. ; Canto, R. B. ; Pessan, L. A.

• Document type: Journal article
• Source: BIOINSPIRATION & BIOMIMETICS; v. 17, n. 4, p. 14-pg., 2022-07-01.

Abstract

The mesocarp of Bertholletia excelsa is a rich source of inspiration for strong, stiff and damage-tolerant composites. The bioinspired composites developed here are composed of an epoxy matrix with a 3D printed polylactic acid reinforced with 30% of carbon fiber (PLA-30CF) inspired in fibers, and syntactic foam inspired by sclereids. Monotonic and cyclic four-point bending tests and compact tension fracture toughness tests were carried out assisted by digital image correlation (DIC) to evaluate flexural properties, damage tolerance, and the R-curve of the composite. Its microstructure and fracture surface were analyzed by scanning electron microscopy. The mechanical performance of the bioinspired composite is promising: density of 1.0 g cm(-3), flexural apparent elastic modulus of 1.6 GPa, and flexural strength six times higher than the neat epoxy, i.e. 17 MPa. Although the PLA-30CF printed structure led to a rising R-curve, the syntactic foam needs optimization to have a synergistic effect. (AU)

• FAPESP's process: 18/23081-0 - Fracture mechanisms of refractories at room and elevated temperatures analyzed with wedge splitting tests and image correlation
• Grantee: Rafael Vargas Maginador
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/02801-4 - Identification of material models for numerical simulation of powder pressing
• Grantee: Rodrigo Bresciani Canto
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/25523-1 - Biomimetics of brazil nut shell: structure and failure analysis
• Grantee: Marilia Sonego
• Support Opportunities: Scholarships in Brazil - Doctorate