Uncertain and sensitivity analyses of a composite shaft

Composite materials have been widely used in engineering applications due to their many advantages over conventional materials. Following this trend, researchers on rotordynamics have shown interest in the replacement of metallic by composite shafts, resulting in higher operating speeds, better efficiency, lower weight, among other positive aspects. In this sense, different models were proposed for the computational modeling of composite shafts such as the so-called Simplified Homogenized Beam Theory (SHBT). SHBT associated with the finite element (FE) method demonstrated to be effective for representing the dynamic behavior of composite shafts operating under subcritical conditions. Many parameters of the composite shaft are required to develop the corresponding model. Small variations on these parameters often modify the dynamic behavior of the shaft. Thus, the application of uncertainty and sensitivity analyses become necessary from the design point of view. In this context, the present contribution aims to apply uncertainty and sensitivity analyses to the SHBT-FE model of a composite hollow shaft. In this case, the interval uncertainty and sensitivity approaches are used. The effects of the uncertain parameters on the dynamic behavior of the shaft are evaluated considering different excitation frequencies. The obtained results demonstrate the importance of the conveyed methodology in the design of composite shafts.