GOALI/Collaborative Research: Understanding and Controlling Variation Propagation in Periodic Structures: From Geometry to Dynamic Response

本合作研究的目的是了解和控制周期性结构中产品几何形状与其动力响应之间的变化传播。制造过程本质上是不精确的，生产出的产品几何形状各异。几何变化不仅会对最终装配的适应性产生不利影响，而且在许多情况下还会影响最终产品的功能。在本研究中，我们将建模和分析周期结构中从制造零件几何形状到其动态响应的变化传播，从而通过控制零件几何形状的平均值和变化来减轻不良的动态响应。所提出的方法包括两个方向的变异传播分析：(1)在正演预测中，基于密集测量来表征制成品的几何变异，然后计算动力响应的概率分布。（ii）在逆向分析中，以异常动态响应作为输入，识别出一组局部几何特征，这些特征经过修改后可以缓解不期望的动态响应。如果研究成功，将对航空发动机和发电设备的叶片盘、高速加工的刀具、空间天线等多种周期性结构产品产生积极影响。通过与通用电气的合作，这项研究将直接惠及许多行业，如航空航天、汽车和制造业，这些行业都使用了这些周期性结构。该项目将通过综合研究、教育和推广活动，为从高中到研究生的学生提供变异传播和减少的先进知识，并提高国内学生的学习水平。对科学和工程的兴趣，从而加强我们在全球劳动力中的竞争力。

The objective of this collaborative research is to understand and control the variation propagation between product geometry and its dynamic response in periodic structures. Manufacturing processes are inherently imprecise, producing products that vary in geometry. The geometry variation detrimentally impacts not only the fitness of the final assembly, but also in many cases the functionalities of the final product. In this research, we will model and analyze the variation propagation in periodic structure from the manufactured part geometry to its dynamic response and then to provide guidelines on mitigating the undesirable dynamic response via controlling the mean and variation of part geometry. The proposed methodology includes variation propagation analysis in two directions: (i) In the forward prediction, the geometry variation of the manufactured products is characterized based on dense measurements, and then the probabilistic distributions of the dynamic responses are computed. (ii) In the backward analysis, using the abnormal dynamic response as input, a group of local geometric features that, upon modification, can mitigate the undesirable dynamic response are identified. If successful, this research will positively impact a variety of periodic structural products, including bladed-disks in aero-engines and power generation equipment, cutting tools in high speed machining, and space antenna, etc. Through the collaboration with General Electric, this research will directly benefit a host of industries such as aerospace, automotive and manufacturing industries where these periodic structures are used. Through its integrated research, education and outreach activities, this project will provide advanced knowledge in variation propagation and reduction for students from high schools to graduate schools and will enhance domestic students? interest in science and engineering and therefore strengthen our competitiveness in the global workforce.