Title:
Tough Bouligand and Double-Bouligand Architected Concrete Enabled by Two-Component Robotic Additive Manufacturing
Author(s):
Arjun Prihar
Publication:
Web Session
Volume:
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
4/2/2023
Abstract:
Nature has developed abundant biological design motifs for arranging modest materials into complex damage-tolerant architectures. The bouligand architecture found in the endocuticle of the mantis shrimp dactyl club is comprised of rows of fibrils forming sheets which helically stack atop each other. The double-bouligand architecture found in the scales of the coelacanth fish are similarly comprised of helically arranged sheets of collagen fibrils, however, each sheet is coupled with a second perpendicular layer of fibrils to form an orthogonal bilayer unit. A two-component robotic additive manufacturing technique was developed to fabricate bioinspired architected concrete beams. The design of the material’s helical architecture was inspired by those found in the bouligand and double-bouligand motifs and their underlying toughening mechanisms. Experimental fracture tests (Mode I) were conducted to characterize fracture toughness and work of fracture and were accompanied by an analytical method. Engineering the bioinspired architectures enabled toughening mechanisms including crack twisting, deflection, and shielding, occurring ahead and behind the crack tip, and resulting in a 60% increase in fracture toughness and 80% increase in work of fracture compared to reference cast counterparts. The bioinspired architectures engender a pathway for leveraging a reliable tensile capacity in design of future concrete structures.