A dynamic geometrically nonlinear isogeometric analysis study for anisotropic auxetic sandwich plates with negative Poisson’s ratio

This study investigates the geometrically nonlinear dynamic response of anisotropic sandwich plates with auxetic (negative Poisson’s ratio) honeycomb cores using isogeometric analysis (IGA). The governing equations incorporate von Kármán nonlinear strains and Rayleigh damping. Different loading conditions, including blast, step, sine, and triangular loadings, are considered. Numerical validations confirm the accuracy and convergence of the proposed approach. Results demonstrate that auxetic cores reduce vibration amplitudes by up to 11.83% compared to positive Poisson’s ratio cores. Geometrically nonlinear effects significantly suppress displacements (up to 19.79%) and shorten vibration periods, particularly under blast loading. Core thickness proportion critically governs nonlinearity, with thicker auxetic honeycomb cores amplifying stiffness hardening. Damping analysis reveals auxetic honeycomb cores lower higher-order vibration frequencies by 20%, benefiting resonance-sensitive applications. This work establishes a computational framework for the geometrically nonlinear dynamic analysis of auxetic sandwich plates under explosive loads based on IGA and demonstrates tunable vibration control through honeycomb core architecture. The proposed framework provides useful insights for the design of blast-resistant and vibration-sensitive sandwich structures in aerospace and precision engineering applications.