This study examines the experimental characterization of three identically 3D printed polylactic acid (PLA)-based cantilever beams subjected to various vibrational excitations with investigating the possible existence of multiple solutions and compares the results of the beams to one another to reveal uncertainties and possible issues of reproducibility of the additively-manufactured systems. Free, random, and harmonic excitations are performed to evaluate the responses of identically manufactured PLA-based beams with focusing on the first three modes of vibrations. The results show that nonlinear damping and nonlinear softening are present for the first three modes of vibration for the systems under consideration. It is proved that significant uncertainties may be found in estimating the linear and nonlinear characteristics of “identically” manufactured beams. It is also demonstrated that the reproducibility of these systems is not feasible from systems under vibratory excitations. In addition, the experiments indicate that the same additively manufactured beam may encounter multi-stable solutions which questions the reliability of manufacturing 3D printed systems subjected to dynamical excitations.

中文翻译：

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PLA 基增材制造梁的弯曲模式实验表征和多稳态解研究


这项研究检查了三个相同的 3D 打印聚乳酸 (PLA) 基悬臂梁在各种振动激励下的实验特性，调查了可能存在的多种解决方案，并将梁的结果相互比较，以揭示不确定性和可能的​​问题增材制造系统的再现性。进行自由、随机和谐波激励，以评估相同制造的 PLA 梁的响应，重点关注前三种振动模式。结果表明，所考虑系统的前三种振动模式存在非线性阻尼和非线性软化。事实证明，在估计“相同”制造的梁的线性和非线性特性时可能会发现显着的不确定性。还证明了这些系统的再现性对于振动激励下的系统是不可行的。此外，实验表明，相同的增材制造光束可能会遇到多稳态解决方案，这对受到动态激励的制造 3D 打印系统的可靠性提出了质疑。