Accurate Measurement of Micromachining Forces in Three Dimensions

微机械加工已越来越多地用于从多种材料制造用于许多应用的高科技微型和小型尺寸的器件。实现微加工工艺的质量和生产率的显著进步对于将微加工转变为工业可行的工艺至关重要。因此，迫切需要对过程和系统特性的基础知识。由于微机械加工力体现和表现的力学，动力学，稳定性和微机械加工过程和系统的健康的关键信息，这些力量的准确测量是至关重要的，以获得基本的理解，从而实现变革性的进步，微机械加工科学和工程。现有的力测量系统不能准确测量微加工力，从而阻碍了进一步的发展。该奖项支持对精确测量三维微加工力的科学和技术研究。该研究将创建一种独特的动态建模方法，为下一代测功机设计提供信息。本项目的研究目标是：（1）了解结构动力学与测力特性之间的关系;（2）了解结构动力学与测力特性之间的关系;（3）了解结构动力学与测力特性之间的关系;（2）创建补偿方法以显著扩展三维测量带宽;以及（3）构建/验证模型以实现未来的测功机设计。为了实现目标1，实验模态分析将进行商业微型加工测力计。将使用定制的冲击激励系统提供动态激励，并使用激光多普勒测振仪测量动态响应。将收集并比较激振（来自冲击系统）和测力计的力。将考虑不同的边界条件（固体、弹性）。通过这些测试，将在0-60 kHz带宽内获得接收和力-力频率响应函数。针对目标2，将使用反向滤波技术来设计补偿方法，以将测量带宽扩展至少20倍。实验验证和功能评价（使用微铣削和微钻工艺）的开发补偿方法将进行。对于目标3，测力计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，将使用频谱切比雪夫技术开发。这些模型也将使用与实现目标1相同的实验模态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.