Full-annular rubbing is a common rubbing form in rotor systems. It introduces an additional constraint on the rotor, which produces a significant increase in the resonance frequency. Although many studies have qualitatively discussed the influence of rubbing on rotor dynamics, the quantitative effect of this constraint still needs to be analyzed with advanced methods and validated by rigorous experiments. The present paper aims to establish a method for predicting the resonance frequency of a rotor undergoing full-annular rubbing. The dynamic feature of a rubbing rotor system is analyzed by complex nonlinear modal analysis, and the numerical results are evaluated against measurements obtained from a rubbing rotor test rig. A modified Jeffcott rotor model is first formulated to clarify the relationship between the modal characteristics and the steady-state response. Experiments are then carried out to investigate the influence of rubbing on rotor dynamics. The results show that the constraint effect caused by rubbing can be quantitatively captured by nonlinear modal analysis.

Rotor-flexible casing rubbing can induce strong nonlinear dynamics in rotor systems. This study investigates the harmonic frequency characteristics of a rubbing rotor system with a flexible casing constraint. A nonlinear rub-impact model combined with a finite element-based rotor–casing coupling framework is developed to evaluate system responses under concentric and eccentric configurations. The harmonic components of rotor and casing vibrations are analyzed over a range of rotational speeds. Results show that, under concentric conditions, harmonic frequencies originate from rubbing-induced asynchronous motion. The harmonic sub-frequencies observed in the spectrum correspond to lobed rotor orbits formed during the transition from synchronous to asynchronous motion under continuous rubbing forces. Under eccentric rotor–casing alignment, the vibration spectrum becomes more complex and exhibits frequency clustering. The results provide insight into harmonic generation mechanisms and highlight the role of casing flexibility in rubbing-induced asynchronous motion.

This study investigates the dynamic mechanism of turbine blade-shaving and the containment performance of multi-thin-wall casings (stacked casings) under blade-off events in aero-engines. An integrated implicit–explicit finite element framework is developed to analyze the transient interactions between released blades and surrounding casings. Results reveal a sequential evolution of blade detachment, inter-blade collision, fragment accumulation, and casing deformation. Dynamic response analysis demonstrates that the first and second casings exhibit progressive bulging and tearing when impact energy exceeds local containment capacity, whereas the third casing prevents fragment egress through substantial plastic deformation. The proposed modeling approach enables high-fidelity prediction of failure progression and offers engineering insights into the optimization of casing design for enhanced containment safety.

To resolve the fatigue fracture occurring at the tip trailing edge of thin-walled single-crystal turbine rotor blades for a specific aero-engine, this paper derives the relationship between the single-crystal constitutive stiffness matrix and crystal orientation, and clarifies the influence mechanism of crystal orientation on blade-vibration characteristics. The influence rules and degrees of uncertain parameters on the vibration characteristics of thin-walled and thickened-profile blades are comparatively investigated. The results reveal that blade dynamic frequency is strongly affected by both blade profile thickness and crystal orientation, and blade profile optimization can effectively weaken the effects of crystal orientation and blade thickness on the dynamic frequency of critical modes. Based on the above results, the hazardous resonance overlooked in conventional engineering approaches is detected using uncertainty-based vibration analysis. The corresponding failure mechanism is illustrated, the resonant speed range is determined, and the risk of bending–torsion coupled flutter is detected. The outcomes provide valuable guidance for the frequency tuning design of turbine blades.

In this paper, the dynamic characteristics of a rotor with disk inertial asymmetry are investigated. A rotor model is developed using the Lagrange method, and a modal analysis technique based on Hill’s determinant is derived. The modal properties and dynamic responses of the asymmetrical rotor are then analyzed. Experimental studies are carried out to validate the resonance broadening phenomenon observed in numerical simulations. Results indicate that the dynamics of such a rotor exhibit multifrequency vibrations and unstable behavior. Notably, these characteristics such as the emergence of resonance bands instead of distinct critical speeds and speed‐dependent instability regions are unique to asymmetric rotors and are not observed in symmetric rotor systems.