The aim of this study is to present a nonlinear model that can describe the free vibration damping behavior of 3D knitted fabrics. A fabric is considered as a single degree of freedom model which consists of a nonlinear spring paralleled with a dashpot both in series with a mass. The differential equations of the system motion are solved using the multiple scales method. Damped frequency ω_d and damping coefficient \(\widehat\mu \) are determined using the approximate analytical method, the Imperialistic Competitive Algorithm (ICA) and linear methods to estimate the system response. The obtained system response is then compared with experimental results. The results of the study show that, in comparison with analytical solutions and linear models, ICA can predict the behavior of spacer fabrics more accurately. It is also found that the difference between experimental and predicted models is explained by errors of 8.3 %, 13.7 % and 16.2 % for ICA, approximate analytical and linear model respectively.

这项研究的目的是提出一个可以描述3D针织面料自由振动阻尼行为的非线性模型。织物被认为是一个单自由度模型，它由一个非线性的弹簧和一个平行于阻尼器的弹簧组成，两者均与质量串联。使用多尺度方法求解系统运动的微分方程。阻尼频率ω _d和阻尼系数\（\ widehat \亩\）使用近似分析方法，Imperialistic竞争算法（ICA）和线性方法确定系统的响应。然后将获得的系统响应与实验结果进行比较。研究结果表明，与解析解和线性模型相比，ICA可以更准确地预测间隔织物的行为。还发现，实验模型和预测模型之间的差异可以通过ICA，近似分析模型和线性模型的误差分别为8.3％，13.7％和16.2％来解释。