Model assessment of a composite mock-up bladed rotor based on its vibration response and radial expansion

Abstract

Composite materials provide high strength and stiffness-to-weight ratios and adjustable directional material properties. As a result, a growing application of composite materials in weight-relevant and complex-loaded structures is noticeable, especially, for the production of high-speed rotors. However, their material complexity, their parameter scatter and unpredictable impact events contribute to the prediction uncertainty of the operational capability.The in situ measurement of damage-sensitive features can provide information for reliable simulation models. Such models are a prerequisite for the analysis of the damage behaviour in practice-relevant loading scenarios.For this purpose, a novel optical measurement system is introduced measuring the rotor deformation. The system offers a measurement rate of 1.6kHz with an 7μm error independent on the rotational speed. Furthermore, the rotor vibration response was identified using a combined excitement-measurement system for different rotational speeds. Both measurement systems were successfully applied on a glass fibre-reinforced composite rotor.Based on the experimental results, a simulation model was adjusted using an advanced mixed numerical–experimental technique. A good compliance between experimental and simulation results was identified for rotor-typical stress states. In addition, the rotor temperature is shown to have a significant influence on the model accuracy and has to be incorporated in future models.