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

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.***