Spiral interface: A reinforcing mechanism for laminated composite materials learned from nature

Yang Gao, Zhenbin Guo, Zhaoqiang Song, Haimin Yao

Research output: Journal article publicationJournal articleAcademic researchpeer-review

13 Citations (Scopus)


In this paper, we studied a helical architecture called microscopic screw dislocation (μ-SD), which is prevalently present in biological laminated composites such as shells of mollusks P. placenta and nacre of abalone. Mechanical characterization indicated that μ-SDs can greatly enhance resistance to scratching. To shed light on the underlying reinforcing mechanisms, we systematically investigated the mechanical behaviors of μ-SD using theoretical modeling in combination with finite element simulation. Our analysis on an individual μ-SD showed that the failure of a μ-SD under tension involves the delamination of the prolonged spiral interface, giving rise to much higher toughness compared to those of the planar counterpart. The corporation of multiple μ-SDs was further investigated by analyzing the effect of μ-SD density on the mechanical reinforcement. It was found that higher areal density of μ-SD would lead to more improvement in toughness. However, the operation of such reinforcing mechanism of μ-SD requires proclivity of cracking along the spiral interface, which is not spontaneous but conditional. Fracture mechanics-based modeling indicated that the proclivity of crack propagation along the spiral interface can be ensured if the fracture toughness of the interface is less than 60% of that of the lamina material. These findings not only uncover the reinforcing mechanisms of μ-SDs in biological materials but imply a great promise of applying μ-SDs in reinforcing synthetic laminated composites.
Original languageEnglish
Pages (from-to)252-263
Number of pages12
JournalJournal of the Mechanics and Physics of Solids
Publication statusPublished - 1 Dec 2017


  • Bio-inspired materials
  • Biomineralized materials
  • Delamination
  • Microscopic screw dislocation

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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