On-Line Monitoring and Prediction of Material Degradation in Mechanical Structures

9531835射线这一分析和实验研究项目的重点是加强复杂机械结构材料损伤在线监测和剩余使用寿命预测的科学技术基础。潜在的应用领域包括汽车和飞机相关的机械系统、发电厂和纸浆和造纸厂，以及离散的生产过程，如陶瓷和半导体的制造，在这些领域，工厂部件的结构耐久性和运行可靠性至关重要。基于对物理现象和现有数据的理解，建立了选定材料在连续时间设置下的损伤动力学解析确定性模型，而不是通常使用的基于循环的疲劳损伤模型。基于一组实验产生的统计数据，提出了疲劳动力学的随机建模。利用基本传感元件串联输入的随机模型，建立了损伤在线监测系统。概念的实验验证是通过实验室制造的测试仪器完成的，设备和测试样品分别由NASA Lewis和Sikorsky飞机公司提供。

9531835 Ray The emphasis of this analytical and experimental research project is to enhance the science and technology base for on- line monitoring of material damage and prediction of residual service life in complex mechanical structures. Potential application areas include automotive and aircraft related mechanical systems, electric power plants, and pulp and paper mills, and discrete production processes such as manufacture of ceramics and semiconductors, where structural durability of plant components and operational reliability are critical. Based on the understanding of physical phenomena and the data available, analytical deterministic models of damage dynamics are formulated for selected materials in a continuous time-setting as opposed to the commonly used cycle-based models of fatigue damage. Stochastic modeling of fatigue dynamics is advanced based on an ensemble of experimentally generated statistical data. An on-line damage monitoring system is built using the stochastic model with series inputs from basic sensing elements. Experimental validation of the concept is accomplished via a test apparatus fabricated in the laboratory with equipment and test samples provided by NASA Lewis and Sikorsky Aircraft Company respectively.***