Fused deposition modelling (FDM) has emerged as an economical additive manufacturing method having the potential to fabricate functional components. Dynamic behaviour of FDM components is of great interest while designing and printing them for functional applications. This paper presents a methodology to describe the dynamic characteristics of FDM, combining the features of thermoplastic material and build parameters adopted in fabrication. The viscoelastic characteristics of thermoplastic filament induce time–temperature dependence in FDM components. The viscoelastic characteristic of the polymer is determined by dynamical mechanical analysis. Layer height is a significant build parameter that determines void geometry even in 100% infill printing, that influences mechanical properties of these additive manufactured components. Dynamic response of FDM 3D-printed parts is highly dependent on viscoelastic characteristics of polymer filaments and build parameters associated with printing. In the study, micro-scale models representing the features of actual cross section morphology with different layer heights are identified as representative volume element (RVE) models. Harmonic analysis is conducted on the RVE models using polymer material data approximated with generalized Maxwell model to determine the dynamic characteristics of the FDM print. The numerical analysis reveals orthotropic viscoelastic nature with maximum stiffness along the direction of filament deposition (raster) direction followed by transverse and vertical directions. A drastic reduction in the FDM component stiffness was observed at lower straining rates. The characteristics determined on RVE can be homogenized to the entire structure based on its print conditions and can be used for designing functional components.

熔融沉积建模（FDM）已经成为一种经济的增材制造方法，具有制造功能组件的潜力。在设计和打印功能性应用程序时，FDM组件的动态行为引起了极大的兴趣。本文提出了一种描述FDM动态特性的方法，结合了热塑性材料的特性和制造中采用的构造参数。热塑性长丝的粘弹性特性会引起FDM组件的时间-温度依赖性。聚合物的粘弹性特征通过动态力学分析确定。层高是一个重要的构建参数，即使在100％填充印刷中，它也会确定空隙的几何形状，这会影响这些增材制造部件的机械性能。FDM 3D打印部件的动态响应高度依赖于聚合物长丝的粘弹性特性以及与打印相关的构建参数。在这项研究中，代表不同层高的实际横截面形态特征的微尺度模型被确定为代表体积元（RVE）模型。使用与广义麦克斯韦模型近似的聚合物材料数据对RVE模型进行谐波分析，以确定FDM打印件的动态特性。数值分析揭示了正交各向异性的粘弹性，沿着丝沉积（光栅）方向以及横向和垂直方向具有最大的刚度。在较低的应变速率下，观察到FDM组件刚度急剧下降。