Asymmetrically architected composite metamaterials: can the deviation from curing temperature be exploited for enhanced thermo-mechanical design?

Lattice-based metamaterials are attracting wide attention for advanced lightweight engineering applications, yet such conventional passive designs are constrained by a limited repertoire of periodic geometries that restricts the attainable range and tunability of mechanical properties. This article proposes a new class of thermo-mechanically active metamaterials, conceptualised as periodic networks of composite beams, to address the typical limitations by enabling in-situ modulation of stiffness and Poisson behaviour. Conventional fibre-reinforced composites suffer from unintended warpage when unsymmetric laminates cool from their curing temperature, and this effect is usually treated as a manufacturing defect to be minimised or corrected. This study explores whether deviation from curing temperature can instead be exploited for enhanced autonomous thermo-mechanical design, introducing the notion of artificially induced physical intelligence. We introduce asymmetrically architected lattices where the cell walls are formed from unsymmetric composite laminates that undergo temperature-dependent shape morphing. Departure from the curing temperature induces controlled anti-curvature or pro-curvature effect at the beam level, which in turn produces mode-dependent stiffening or softening of the effective in-plane elastic moduli of the metamaterial without any lattice-level warping. An efficient semi-analytical framework, combining finite element beam analyses with homogenisation at the lattice scale, quantifies the thermo-mechanical behaviour, demonstrating curing temperature deviation as a deliberate design variable for enhanced mechanical designs and active constitutive control.