Nonlinear Dynamic Modeling of Fiber-Reinforced Composite Truncated Conical Shell with Large Deformation: A Theoretical and Experimental Study

This paper presents a novel nonlinear vibration model for fiber-reinforced composite thin-walled truncated conical shells (FRCTWTCS), uniquely considering both amplitude and strain dependencies, which has not been comprehensively addressed in previous studies. The stress–strain relationship between fiber layers is derived using the enhanced Jones-Nelson nonlinear theory combined with von Kármán’s large deformation theory, providing a more accurate representation of material nonlinearity under large deformations. Unlike existing models that primarily focus on geometric nonlinearity, this study incorporates material nonlinearity (e.g. stiffness softening) and amplitude-dependent effects, offering a more comprehensive framework for predicting nonlinear vibrations. The nonlinear vibration characteristics and fitting parameters are determined using the energy method and Particle Swarm Optimization (PSO), with damping computed using the complex modulus method. To validate the proposed model, an experimental study on a TC300/epoxy resin truncated conical shell is conducted, demonstrating a maximum error of only 2.5% in natural frequencies and 5.1% in vibration responses, significantly improving upon the accuracy of existing models. Furthermore, the study systematically explores the influence of various constraints, including boundary lengths, semi-cone angles, and fiber layup orientations, on the nonlinear vibration characteristics, providing new insights into the dynamic behavior of FRCTWTCS under different operational conditions.