Despite the proliferation of cellular fused filament fabrication (FFF) polymer components for a variety of industrial applications, few studies have investigated their fluid-structure interaction (FSI) behavior during loading, particularly under dynamic impact conditions. Furthermore, the extent to which residual stresses from the FFF build process affect the dynamic load bearing characteristics has not been addressed. In this work, simulations and experiments are conducted for cylindrical nylon specimens fabricated with two different internal closed-cell cavity structures to assess the influence of the entrapped fluid and the FFF residual stresses on the state of stress during high strain-rate impact. The demonstrated 2-stage computational approach includes a thermomechanical model of the FFF build to calculate residual stress and distortion, which forms the initial state for a subsequently executed dynamic impact model using smoothed particle hydrodynamics (SPH) to capture the effects of air within the internal cavities. Dynamic displacement boundary conditions for the FSI simulations are identified using digital image correlation (DIC), obtained from impact experiments on the FFF specimens performed using split Hopkinson pressure bar (SHPB) tests. Findings reveal that FFF residual stresses significantly influence the stress-strain response during dynamic impact, even at strain rates of 500-600 s⁻¹. In addition, while the influences of both FFF residual stress and FSI vary with internal cellular structure, the study reveals that their coupled effects must be considered to accurately characterize the impact behavior. Validity of the 2-stage numerical approach, as well as significance of FFF residual stress and the influence of FSI, are justified by comparing numerical predictions with experimental measurements, and observing root-mean-square stress errors within 12.77% and 11.87%, and peak stress errors within 1.93% and 1.34% for the two specimens.

尽管蜂窝熔丝制造（FFF）聚合物组件已在多种工业应用中激增，但很少有研究调查了它们在加载过程中的流体-结构相互作用（FSI）行为，特别是在动态冲击条件下。此外，还没有解决FFF生成过程中残余应力影响动态承载特性的程度。在这项工作中，对用两种不同的内部闭孔腔结构制成的圆柱形尼龙试样进行了仿真和实验，以评估截留流体和FFF残余应力对高应变率冲击过程中应力状态的影响。演示的两阶段计算方法包括FFF结构的热力学模型，用于计算残余应力和变形，它使用平滑粒子流体动力学（SPH）形成随后执行的动态冲击模型的初始状态，以捕获内部空腔中空气的影响。FSI模拟的动态位移边界条件是使用数字图像相关性（DIC）来识别的，该数字图像相关性是通过使用霍普金森压力棒（SHPB）分离试验对FFF样品进行的冲击实验获得的。研究结果表明，FFF残余应力即使在500-600 s的应变速率下也能显着影响动态冲击过程中的应力-应变响应。FSI模拟的动态位移边界条件是使用数字图像相关性（DIC）来识别的，该数字图像相关性是通过使用霍普金森压力棒（SHPB）分离试验对FFF样品进行的冲击实验获得的。研究结果表明，FFF残余应力即使在500-600 s的应变速率下也能显着影响动态冲击过程中的应力-应变响应。FSI模拟的动态位移边界条件是使用数字图像相关性（DIC）来识别的，该数字图像相关性是通过使用霍普金森压力棒（SHPB）分离试验对FFF样品进行的冲击实验获得的。研究结果表明，FFF残余应力即使在500-600 s的应变速率下也能显着影响动态冲击过程中的应力-应变响应。^-1。此外，尽管FFF残余应力和FSI的影响随内部细胞结构而变化，但该研究表明必须考虑它们的耦合作用才能准确表征冲击行为。通过将数值预测与实验测量值进行比较，并观察均方根应力误差在12.77％和11.87％之内，可以证明两阶段数值方法的有效性以及FFF残余应力的重要性和FSI的影响。两个样品的最大应力误差在1.93％和1.34％之内。