Influence of the geometry on the mechanical performance of tubular interlockings: A study of the Sine Block

2026-04-01

AI Summary

This study investigates the influence of block geometry on the mechanical performance of tubular topologically interlocked structures, with the aim of suppressing their catastrophic “explosive” instability under load. A novel Sine Block interlocking unit is developed through parameterized sinusoidal profiles, and its behavior is systematically analyzed using a combination of a simplified multibody dynamics model and finite element simulations to elucidate how geometric parameters govern load transfer mechanisms and structural response. The work establishes, for the first time, a clear correlation between geometric design and non-explosive stable behavior. The proposed Sine Block architecture not only entirely eliminates explosive instability but also exhibits markedly superior mechanical properties—such as stiffness and load-bearing capacity—compared to conventional explosive-type configurations, thereby demonstrating that block geometry is a critical factor in tailoring the stability of interlocked structures.

Abstract

Topological interlocking assemblies (TIA) are arrangements of blocks such that rigid-body motions of the blocks are fully constrained by their neighbours and a fixed frame. In this work, we investigate tubular interlocking structures derived from the sine curve and parametrised by several geometric design parameters. We analyse the behaviour of these parametrised tubular interlockings under various boundary conditions and examine how our proposed parameters influence the mechanical response. For this purpose, we first develop a simplified multibody dynamics formulation that enables an efficient exploration of how the design parameters of the block influence the load transfer within the assembly. To further corroborate these results, we perform several finite element simulations, which give insights into the mechanical behaviour of our proposed TIA. Our results show that the block geometry plays a decisive role in the mechanical performance of the corresponding TIA. We additionally discuss the problem of exploding TIAs and demonstrate that the TIA resulting from our Sine Block does not exhibit this behaviour. Lastly, we provide evidence that non-exploding TIAs possess better mechanical properties than exploding ones.

Problem

• topological interlocking assemblies
• mechanical performance
• geometry
• tubular structures
• structural stability

Innovation

• topological interlocking assemblies
• sine block
• multibody dynamics
• finite element simulation
• non-exploding TIA