Prediction of fatigue damage and residual useful life for composite structures using passive sensing

This paper presents a new prognosis model and experimental validation of a real-time health monitoring and residual useful life (RUL) prediction for composite structures. On-line damage states are estimated with real-time sensing information and are fed to an off-line predictive model to update future damage states and RUL. A new damage index is defined to quantify the quantitative damage state information at any particular fatigue cycle. The prognosis model is capable of estimating the cumulative fatigue damage in composite test structures under constant amplitude loading and estimating the RUL. The uniaxial tensile loading fatigue tests are followed by biaxial loading tests with a MTS biaxial tension/torsion test frame. Numerical validations demonstrate that the predictive capability of the prognosis algorithm is effective in predicting the RUL even under complex stress states.