Thin shells are widely used in structural design and developing lightweight high-performance materials and composites. A fluid coating-assisted additive manufacturing method proposed in the literature shows great potential in fabricating lightweight composites using shell-like framework architectures. However, understanding the fabrication of thin shells by controlling the fluid rheology for a submillimeter-thin coating is still limited. As a demonstration, we investigated the effect of surface tension and yield stress of cement paste on the spreading and stabilisation on a curved honeycomb scaffold to form a thin-shell structure via a lattice-Boltzmann method simulation. We found the coating of cement paste is governed by the coupling effect of surface tension (γ) and yield stress (σ_y), which not only controls the stability but also affects its geometry. The optimal ranges of γ and σ_y were determined and their correlation was derived as a design guideline for future development of this cementitious thin-shell structure. As well, equivalent microscale rheological parameters (γ = 0.015 N/m and σ_y = 3.42 Pa) were identified. This study improves our understanding of the fabrication of high-performance cementitious shells and sheds light on the fabrication of submillimetre-thin shells using a wide range of materials.

薄壳广泛用于结构设计和开发轻质高性能材料和复合材料。文献中提出的流体涂层辅助增材制造方法在使用壳状框架结构制造轻质复合材料方面显示出巨大潜力。然而，通过控制亚毫米薄涂层的流体流变学来理解薄壳的制造仍然是有限的。作为演示，我们通过格子-玻尔兹曼方法模拟研究了水泥浆体的表面张力和屈服应力对弯曲蜂窝支架的铺展和稳定以形成薄壳结构的影响。我们发现水泥浆的涂层受表面张力 ( γ ) 和屈服应力 ( σ_y )，它不仅控制稳定性，而且影响其几何形状。确定了 γ 和σ _y的最佳范围，并推导出它们的相关性，作为这种水泥薄壳结构未来发展的设计指南。此外，还确定了等效的微尺度流变参数（ γ  = 0.015 N/m 和σ _y  = 3.42 Pa）。这项研究提高了我们对高性能水泥壳制造的理解，并阐明了使用各种材料制造亚毫米薄壳的方法。