Internal 3D cracks evolution and the toughening mechanisms of the hierarchical structures in Strombus gigas shell

• Published in: Materials & design Vol. 212; p. 110211
• Main Authors: Zha, Zhenbin, Xu, Feng, Li, Yongcun, Xiao, Yu, Hu, Xiaofang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15-12-2021; Elsevier
• Subjects: Crack propagation; Hierarchical structure; Synchrotron radiation X-ray computed tomography; Toughening mechanism; Weak interface; Weak interface; Synchrotron radiation X-ray computed tomography; Toughening mechanism; Hierarchical structure; Crack propagation
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2021.110211

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•Internal 3D deformation and fracture of Strombus gigas shell was in-situ studied.•Cracks propagation such as multi-point initiation, reversed deflection were observed.•Stress, structure and weak interface coupled toughening mechanisms were proposed.
Strombus gigas shell is a lightweight, high-strength and high-toughness biocomposite material. In-depth exploration of its internal microstructure characteristics and the corresponding strengthening and toughening mechanism is of great significance to the design of high-performance composite materials. Here, the high-resolution synchrotron radiation X-ray computed tomography technology was adopted to carry out the in-situ three-dimensional investigation on the deformation and fracture evolution of the internal crossed-lamellar hierarchical structures of the Strombus gigas shell during the tensile process. In the experiment, some important three-dimensional crack initiation and propagation evolution phenomena were observed, such as the multi-point bursting, progressive propagation and spatial network arrangement of cracks and the reverse ‘C’-shaped cracks, which may have great contribution to the load-bearing capacity and toughness of the shell. According to the mechanical analysis of the visualized evolutionary information of the deformation and fracture of hierarchical microstructures, a strengthening and toughening regulation mechanisms that driven by the local stress concentration, and guided by the hierarchical structure and weak interface was proposed. This study may have a positive guiding significance for exploring and learning the toughening design strategy of lightweight composites.