On the effect of mass and stiffness unbalance on helicopter tail rotor system behavior

Purpose – This study aims to investigate the effects of mass and stiffness imbalance in a tail rotor induced by damage in forward flight. Design/methodology/approach – An aeroelastic analysis based on finite element in space and time and capable of modeling dissimilar blades is carried out to study the effect of damage occurring in one, two, and three blades in a four-bladed tail rotor system in forward flight. The effect of damage growth on vibratory hub loads and blade responses is studied using a comprehensive aeroelastic code. Findings – The diagnostic chart which is the summary of damage analysis of tail rotor shows that the root hub vibration spectrum gives enough indication to predict damage growth in the tail rotor blade. Hence, this can be useful towards development of health monitoring system for tail rotor blades. Originality/value – The proposed analysis helps in understanding the basic physics behind the damaged tail rotor and also gives qualitative assessment of damaged tail rotor where obtaining the flight test data with damaged tail rotor is difficult.

[1]  Prashant M. Pawar,et al.  Active twist control methodology for vibration reduction of a helicopter with dissimilar rotor system , 2009 .

[2]  Prashant M Pawar,et al.  Structural Health Monitoring Of Composite Helicopter Rotor Blades , 2006 .

[3]  Yihua Cao,et al.  Numerical simulation of turbulent flow around helicopter ducted tail rotor , 2005 .

[4]  Ranjan Ganguli,et al.  On the effect of matrix cracks in composite helicopter rotor blade , 2005 .

[5]  Ranjan Ganguli,et al.  Health monitoring of a helicopter rotor in forward flight using fuzzy logic , 2002 .

[6]  Ranjan Ganguli,et al.  OPTIMUM DESIGN OF A HELICOPTER ROTOR FOR LOW VIBRATION USING AEROELASTIC ANALYSIS AND RESPONSE SURFACE METHODS , 2002 .

[7]  A Evans,et al.  Flight deck indication of health monitoring data—a critique , 2002 .

[8]  Ajay Sehgal,et al.  Design And Development Of A Four-Bladed Tail Rotor System For The USMC H-1 Upgrade Program , 2001 .

[9]  Anindya Ghoshal,et al.  Damage Detection Testing on a Helicopter Flexbeam , 2001 .

[10]  Inderjit Chopra,et al.  Simulation of Helicopter Rotor-System Structural Damage, Blade Mistracking, Friction, and Freeplay , 1998 .

[11]  Brian D. Larder,et al.  An Analysis of HUMS Vibration Diagnostic Capabilities , 1997 .

[12]  Lewis Zion,et al.  Some Simple Approaches to Reliable Fatigue Damage Prediction , 1997 .

[13]  Inderjit Chopra,et al.  Formulation of a Helicopter Rotor System Damage Detection Methodology , 1996 .

[14]  Inderjit Chopra,et al.  Detection of Helicopter Rotor System Simulated Faults Using Neural Networks , 1996 .

[15]  Olivier A. Bauchau,et al.  Dynamic analysis of bearingless tail rotor blades based on nonlinear shell models , 1994 .

[16]  Matthew J. O'Rourke,et al.  Simulation Model for Tail Rotor Failure , 1994 .

[17]  Matthew O'rourke.  A simulation model for tail rotor failure , 1992 .

[18]  H Azzam,et al.  The use of Math-Dynamic Models to Aid the Development of Integrated Health and Usage Monitoring Systems , 1992 .

[19]  R. J. Scavuzzo,et al.  Impact ice stresses in rotating airfoils , 1990 .

[20]  D. Banerjee,et al.  Aeroelastic characteristics of the AH-64 bearingless tail rotor , 1988 .

[21]  G S Campbell,et al.  A Survey of Serious Aircraft Accidents Involving Fatigue Fracture. Volume 2. Rotary-Wing Aircraft (Etude sur des Accidents Importants d'Avions du aux Effets des Fractures de Fatigue. Volume 2. Effets sur des Helicopteres). , 1983 .