Dynamic contact characteristics of a rotating twisted variable-section blade with breathing crack
Crack failures frequently occur in aero-engine blades which can trigger a cascade of accidents.Previous studies have primarily focused on crack-induced nonlinear vibration,and the contact state of the crack surfaces during crack breathing is often neglected.However,it is important to consider the contact behavior of the crack surfaces as it is responsible for generating nonlinear vibrations.To further investigate the mechanism behind crack-induced nonlinear vibrations,a novel dynamic contact breathing crack model(DCBCM)for rotating blades is proposed based on the self-programmed incompatible hexahedral element(SNCHE).The breathing effect is simulated using spring elements.The proposed DCBCM is validated by the contact finite element model.Moreover,the effects of crack parameters(depth and location)and load parameters(aerodynamic amplitude and aerodynamic frequency)on the dynamic contact characteristics are investigated.Furthermore,a breathing crack quantification indicator(BCQI)is proposed to represent the nonlinear level of breathing crack.The results indicate that the crack may close from the sides of the blade toward the center of the crack front during crack breathing.Besides,the BCQI increases with the increase of crack depth,aerodynamic amplitude,and rotational speed;while decreases as the crack moves closer to the blade tip.
breathing crackdynamic contact characteristicsrotating bladenonlinear dynamicincompatible hexahedral element
汪伟伟、马辉、赵晨光、吴志渊、王洪基
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School of Mechanical Engineering and Automation,Northeastern University,Shenyang 110819,China
Key Laboratory of Vibration and Control of Aero-propulsion Systems,Ministry of Education,Northeastern University,Shenyang 110819,China
Wuhan Lotus Cars Co.,Ltd.,Wuhan 430024,China
State Key Laboratory of Mechanical System and Vibration,Shanghai Jiao Tong University,Shanghai 200240,China
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