Accurate Measurement of Micromachining Forces in Three Dimensions

微机械加工越来越多地被用来从各种材料中制造高科技的微型和微型器件，用于许多应用。实现微加工过程的质量和生产率的显著进步对于将微机械加工转变为工业可行的过程至关重要。因此，迫切需要有关工艺和系统特性的基本知识。由于微加工力体现和显示了有关微加工过程和系统的力学、动力学、稳定性和健康的关键信息，因此准确测量这些力对于从根本上理解微机械加工科学和工程至关重要，从而实现微机械加工科学和工程的革命性进步。最先进的力测量系统无法精确测量微加工作用力，从而阻碍了进一步的进步。该奖项支持精确测量三维微加工力的科学技术研究。这项研究将创造一种独特的动态建模方法，为下一代测功机的设计提供信息。该项目的研究目标是(1)了解测功机的结构动力学和力测量特性之间的关系；(2)创造补偿方法以显著扩展三维测量带宽；(3)构建/验证模型以支持未来的测功机设计。为了实现目标1，将在商用微型机械加工测功机上进行实验模态分析。动态激励将使用定制的冲击激励系统提供，动态响应将使用激光多普勒测振仪进行测量。将收集(来自冲击系统的)激励和来自测功机的力，并对其进行比较。将考虑不同的边界条件(固体、弹性)。从这些测试中，将获得0-60 kHz带宽内的电感和力-力频率响应函数。对于目标2，将使用逆滤波技术来设计一种补偿方法，以将测量带宽扩大至少20倍。将对开发的补偿方法进行实验验证和功能评估(使用微细研磨和微钻孔工艺)。对于目标3，将使用SPECTRUM-Tchebychev技术建立测功机结构的结构-动力学模型，包括不同的边界条件和工件动力学。这些模型还将使用与实现目标1相同的实验模式分析技术进行实验验证。

Micromachining has been increasingly used to manufacture high-tech micro- and miniature-scale devices from a variety of materials for many applications. Realizing significant advances in the quality and productivity of micromachining processes is vital to transform micromachining into an industrially-viable process. Thus, fundamental knowledge on process and system characteristics are urgently needed. Since micromachining forces embody and manifest critical information on the mechanics, dynamics, stability, and health of the micromachining processes and systems, accurate measurement of those forces is paramount to gaining fundamental understanding on, and thus, to realize transformative advances in, micromachining science and engineering. The state-of-the-art force measurement systems are incapable of measuring micromachining forces accurately, thereby hindering further advancements. This award supports scientific and technological investigations on accurate measurement of three-dimensional micromachining forces. The research will create a unique dynamic modeling approach to inform next-generation dynamometer designs. They will facilitate tremendous advances in the capability to manufacture a myriad of micro- and miniature-scale devices for many fields, including medical/biomedical, aerospace, military/defense, and consumer products.The research objectives of this project are (1) to understand the relationship between structural dynamics and force measurement characteristics of dynamometers; (2) to create compensation approaches to significantly expand three-dimensional measurement bandwidth; and (3) to construct/validate models to enable future dynamometer designs. To achieve Objective 1, experimental modal analyses will be conducted on commercial miniature machining dynamometers. The dynamic excitation will be provided using a custom impact excitation system, and the dynamic response will be measured using laser Doppler vibrometery. Both the excitation (from the impact system) and the forces from the dynamometer will be collected and compared. Different boundary conditions (solid, elastic) will be considered. From these tests, both the receptance and force-to-force frequency response functions will be obtained within the 0-60 kHz bandwidth. Towards Objective 2, inverse-filtering techniques will be used to devise a compensation approach to expand the measurement bandwidth by at least 20 folds. Both experimental validation and functional evaluation (using micromilling and microdrilling processes) of the developed compensation approach will be performed. For Objective 3, structural-dynamics models of the dynamometer structure, including different boundary conditions and workpiece dynamics, will be developed using the spectral-Tchebychev technique. These models will also be experimentally validated using the same experimental modal analysis techniques as those for achieving Objective 1.