Inspiring nested modular structure for axial compression performance

Abstract

Modular structures can adapt to different energy absorption scenarios by changing the assembly form. In this work, inspired by Chinese window frames, four-leaf clovers, cotton rose hibiscus, and maze, a variety of nested modular (NM) structures are proposed with aluminum square tube as base platform. The finite element model of aluminum square tube (AST) is verified through quasi-static compression experiments. Building upon the above, a hierarchical aluminum square tube (HAST) structure is further proposed for enclosing multi-module nested modular (M-NM) structures. Five nested components, namely plum octagonal nested modular structure (PONM), square fluted tube nested modular structure (SFTNM), floral layered nested modular structure (FLNM), square spiral nested modular structure (SSNM), square spiral distributed nested modular structure (SSDNM), are combined with these two platforms, thus generated ten typical NMs. These NM models exhibit two deformation modes, namely the progressive folding of multilobe flaps and the hybrid of outward expansion and progressive folding. M-PONM looks like "jackfruit" after being compressed. Furthermore, the effects of reducing nested components and employing hybrid assembly techniques are further explored. The results indicate that the proposed NM structures significantly enhance the compressive resistance and stability of AST. It is noteworthy that reducing nested components weakens the coupling effects, while hybrid assembly has the opposite effect. In summary, this work provides a series of novel NM structures, providing new ideas for the design of energy absorbing structures.