【摘要】 本文旨在研究3D打印聚乳酸(Polylactic Acid, PLA)喷丝“纤维”不同取向及表面纤维增强对试样力学性能的影响。首先，利用材料试验机分别测定不同纤维取向打印试样的名义弹性模量；然后，基于各向同性与正交各向异性理论构建3D打印PLA蜂窝板的有限元模型，并对悬臂蜂窝结构板的振动模态及固有频率进行数值模拟；最后，采用时间平均-实时相减电子散斑干涉技术，实验测量了悬臂3D打印PLA蜂窝板的振动模态与固有频率。实验结果表明，3D打印PLA蜂窝板具有显著的正交各向异性特征，且表面单向碳纤维增强对蜂窝板弯曲刚度的提升效果优于对扭转刚度的增强。更多还原

【Abstract】 This study investigated the influence of filament orientation and surface fiber reinforcement on the mechanical performance of three-dimensional(3D) printed Polylactic Acid(PLA) specimens. Firstly, a universal testing machine was used to determine the nominal elastic moduli of samples printed with different filament orientations. Next, finite element models of PLA honeycomb panels based on isotropic and orthotropic theories were developed to simulate the vibration modes and natural frequencies of cantilevered honeycomb structures. Concurrently, time-averaged real-time subtraction electronic speckle pattern interferometry(ESPI) was employed to experimentally measure the vibration modes and natural frequencies of the same cantilevered panels. The results demonstrate that 3D printed PLA honeycomb panels exhibit pronounced orthotropic anisotropy. Moreover, vibration tests reveal that unidirectional carbon-fiber surface reinforcement enhances bending stiffness significantly more than torsional stiffness.更多还原