【标题】Hybrid control of electrohydrodynamic 3D printer cone jet
【参考中译】电流体动力3D打印机锥形射流的混合控制
【类型】 期刊
【关键词】 Electrohydrodynamic 3D printer; Taylor cone jet; gray box model; hybrid control; tracking control; hybrid observer; PARAMETERS; POLYMER; INKS
【参考中译】 电流体动力3D打印机;泰勒锥射流;灰箱模型;混合控制;跟踪控制;混合观测器;参数;聚合物;油墨
【作者】 Mohammadi, Kaivan; Abdullahi, Mohammad A.; Salarieh, Hassan; Movahhedy, Mohammad R.; Mohammadi, Sasan
【摘要】 In this article, the control of an electrohydrodynamic 3D printer is studied. The proposed controller has a hybrid piecewise linear feedback form which is designed based on a hybrid model of the printer. The hybrid model is obtained via a gray box identification process whose structure is proposed utilizing the results of the finite element simulation of the printer within the COMSOL Multiphysics software. The asymptotic stability of the hybrid control combined with a hybrid observer is proven using the Lyapunov theory. In addition, the obtained control is applied to the finite element model of the printer to check its performance which shows the success of the controlled system in tracking the reference height for the printer jet cone.
【参考中译】 本文对电液动力3D打印机的控制进行了研究。所提出的控制器具有基于打印机混合模型设计的混合分段线性反馈形式。混合模型是通过灰箱识别过程得到的，其结构是利用COMSOL多物理软件中打印机的有限元仿真结果提出的。利用李亚普诺夫理论证明了混合控制器与混合观测器相结合的渐近稳定性。此外，将所得到的控制应用到打印机的有限元模型中，对其性能进行了检查，表明控制系统成功地跟踪了打印机喷嘴锥体的参考高度。
【来源】 Proceedings of the Institution of Mechanical Engineers, Part E. Journal of Process Mechanical Engineering 2023, vol.237, no.4
【入库时间】 2023/12/27
【标题】Forming quality optimization and microstructure analysis of multilayer coatings with laser powder-fed additive manufacturing
【参考中译】激光送粉添加剂制造多层涂层成形质量优化及组织分析
【关键词】 Multilayer cladding; response surface method; optimization; forming quality; solidification
【参考中译】 多层熔覆；响应面法；优化；成形质量；凝固
【作者】 Ning Lv; Haitao Yue; Chenguang Guo; Lijuan Zhao; Qiang Li; Jianzhuo Zhang; Yin Zhang
【摘要】 To clarify the parameters interaction effects and improve the forming quality of Fe-Cr alloy multilayer laser powder-fed additive manufacturing (LPF-AM) on AISI 4340 substrate, experimental research for Fe-Cr alloy multilayer LPF-AM was carried out via the response surface method (RSM). The interaction effects and evolution rules of laser energy density ( E ), powder feed rate ( Q ), and Z -axis increment ( h ) on minimum cladding height, deposition efficiency and surface spheroidization defects were discussed. The multiobjective particle filter resampling particle swarm optimization (MORPSO) algorithm was adopted to optimize the processing parameters. The phase transformation, grain growth, and microhardness of multilayer LPF-AM were analyzed. The results showed that the powder feed rate and Z -axis increment were found to affect the minimum cladding height and deposition efficiency, respectively. Laser energy density played an essential role in spheroidization defects. The forming quality was significantly improved based on the optimal process parameters of E ?=?33?J/mm~(2), Q ?=?0.5?g/s, and h ?=?0.8?mm. The primary and secondary remelting zones are fine equiaxed dendrites and irregular cellular structures, respectively, and the microstructure of the cladding tracks and layers showed a good metallurgical bonding. The microhardness of the cladding layer ranged from 321?±?18 to 625?±?24 HV_(0.5), and the average microhardness is twice that of the AISI 4340 substrate.
【参考中译】 为明确Fe-Cr合金多层激光送粉增材制造（LPF-AM）工艺参数间的交互作用，提高AISI 4340基体的成形质量，采用响应面法（RSM）对Fe-Cr合金多层LPF-AM进行了实验研究。讨论了激光能量密度（E）、送粉速率（Q）和Z轴增量（h）对最小熔覆高度、熔敷效率和表面球化缺陷的交互作用及其演化规律。采用多目标粒子滤波剩余粒子群优化算法（MORPSO）对工艺参数进行优化。分析了LPF-AM多层膜的相变、晶粒长大和显微硬度。结果表明，送粉速率和Z轴增量分别影响最小熔覆高度和沉积效率。激光能量密度对球化缺陷的形成起着至关重要的作用。采用最优工艺参数E =？33岁？J/mm~ 2，Q =？0.5？g/s，h？=？0.8？一次重熔区为细小的等轴枝晶，二次重熔区为不规则的胞状组织，熔覆轨迹与熔覆层的显微组织呈良好的冶金结合。熔覆层的显微硬度为321？±？18至625？±？24 HV_（0.5），平均显微硬度是AISI 4340基体的2倍。
【来源】 Proceedings of the Institution of Mechanical Engineers, Part B. Journal of engineering manufacture 2023, vol.237, no.11
【标题】Partition-based Print Sequence Planning and Adaptive Slicing for Scalar Field-based Multi-axis Additive Manufacturing
【参考中译】标量场多轴加法制造中基于划分的印刷序列规划与自适应切片
【关键词】 Adaptive slicing; Collision-free printing; Multi-axis additive manufacturing; Process planning; Support-free printing
【参考中译】 自适应切片;无碰撞打印;多轴增材制造;工艺规划;无支撑打印
【作者】 Lau T.Y.; He D.; Li Z.; Tang K.; Chen L.
【摘要】 While multi-axis additive manufacturing is found to be a good solution to the inherent limitations of conventional 2.5D additive manufacturing, it is a much more sophisticated process. Among different existing multi-axis process planning algorithms, we are interested in those based on a scalar field, in which print slices are the iso-surfaces of a scalar field embedded in the 3D model. In this paper, we propose a partitioned-based print sequence planning algorithm and an adaptive slicing algorithm, which together determine a complete multi-axis printing process for an arbitrary solid model. The first algorithm iteratively subdivides the model into a set of components such that a collision-free print sequence can be established among the components. The second algorithm then extracts print slices from each component such that all these slices satisfy the self-support condition. Since an arbitrary model may not satisfy both the self-support and collision-free requirements, we also define certain critical printability rules at the beginning to check whether a given input model with its associated scalar field is printable. The generated print slices and print sequence by the proposed two algorithms are guaranteed to be printable. Furthermore, a shorter total fabrication time and a better surface quality are achieved. Physical experiments of four test models are performed on a homebuilt multi-axis FDM printer, whose results verify the capabilities of the proposed algorithms.
【参考中译】 虽然多轴加法制造被发现是解决传统2.5D加法制造固有局限性的一个很好的解决方案，但它是一个复杂得多的工艺。在现有的各种多轴工艺规划算法中，我们感兴趣的是基于标量场的多轴工艺规划算法，其中打印切片是嵌入在三维模型中的标量场的等值面。本文提出了一种基于分割的打印序列规划算法和一种自适应切片算法，它们共同决定了任意实体模型的完整多轴打印过程。第一种算法迭代地将模型细分为一组组件，从而可以在组件之间建立无冲突的打印序列。然后，第二种算法从每个组件中提取打印切片，使得所有这些切片都满足自支撑条件。由于任意模型可能不同时满足自支持和无冲突的要求，我们还在开始时定义了某些关键的可打印性规则，以检查给定的输入模型及其关联的标量字段是否可打印。两种算法生成的打印切片和打印序列都是可打印的。此外，还获得了更短的总制造时间和更好的表面质量。在自制的多轴FDM机上进行了四个测试模型的物理实验，实验结果验证了所提算法的有效性。
【来源】 Computer-Aided Design 2023, vol.163