Abstract
Journal of the Mechanics and Physics of Solids 2026, 217, 106824
A Coupled Diffusion鈥揗echanics Isogeometric Kirchhoff鈥揕ove Thin-Shell Framework for Architected Materials and Structures
K. Ma, Y. Zhu, and Y. Bazilevs
We develop a coupled diffusion鈥搈echanics isogeometric Kirchhoff鈥揕ove (KL) thin-shell framework for architected materials and structures. The formulation extends KL shell analysis to multiphysics settings in which stress and mass transport interact strongly, while preserving exact Non-Uniform Rational B-Splines (NURBS)-based geometry representation and the smoothness requirements of KL kinematics. Starting from a three-dimensional coupled continuum theory, the governing equations are specialized to thin shells and combined with linear and exponential through-thickness concentration representations, a fully coupled semi-discrete formulation, consistent tangent matrices, and a co-rotational constitutive update with plane-stress enforcement. The framework is first verified through hydrogen-assisted cracking benchmarks and targeted through-thickness verification tests, and is then applied to point-defect-diffusion-induced anelasticity in single-crystalline nanowires and in sheet triply periodic minimal surface (TPMS)-based architected thin-walled structures. The results show that the proposed formulation accurately captures stress-assisted diffusion, diffusion-induced deformation, and pronounced through-thickness concentration variations across benchmark, nanoscale, and architected-shell applications, thereby providing a general computational framework for the multiphysics analysis of thin-walled architected materials and structures.