Structures Perspective for Strength and Fatigue Prognosis in Composites with Manufacturing Irregularities

摘要

Recent advances in understanding deformation and failure mechanisms of polymer-matrix composites used in rotor structures enable accurate and efficient measurement of material stiffness, strength, and fatigue characteristics based on testing small unidirectional laminate specimens. Successful failure predictions provided increased confidence in the development of virtual test methods replacing some of the standard tests of multidirectional laminated composite materials with three-dimensional models accurately predicting deformation, damage topography, strength, and cycles to failure. However, the remaining key questions are related to the ability of transitioning the material-scale virtual test information to larger composite structures. This work presents results of the feasibility assessment targeting the scaling of knowledge and methods acquired at the material scale, to larger structural elements. In particular, manufacturing irregularities such as voids and fiber waviness are typical attributes of composite rotor structures. Therefore, a comprehensive structural analysis should be able to model such irregularities to predict structural strength and fatigue behavior.