Structural design optimization of a tiltrotor aircraft composite wing to enhance whirl flutter stability

Abstract In order to enhance the aeroelastic stability of a tiltrotor aircraft, a structural optimization framework is developed by applying a multi-level optimization approach. Each optimization level is designed to achieve a different purpose; therefore, relevant optimization schemes are selected for each level. Enhancement of the aeroelastic stability is selected as an objective in the upper-level optimization. This is achieved by seeking the optimal structural properties of a composite wing, including its mass, vertical, chordwise, and torsional stiffness. In the upper-level optimization, the response surface method (RSM), is selected. On the other hand, lower-level optimization seeks to determine the local detailed cross-sectional parameters, such as the ply orientation angles and ply thickness, which are relevant to the wing structural properties obtained at the upper-level. To avoid manufacturing difficulties, only a few discrete ply orientation angles and an integral number of plies are considered as constraints. A genetic algorithm is selected as the optimizer at the lower-level. Use of the upper-level optimization causes a 13–18% increase in the flutter speed when compared to the baseline configuration. In the lower-level optimization, the optimization results were obtained considering the resulting failure margin and the location of the shear center.

[1]  Ranjan Ganguli,et al.  Optimal placement of trailing-edge flaps for helicopter vibration reduction using response surface methods , 2007 .

[2]  Taehyoun Kim,et al.  Analysis of tiltrotor whirl flutter in time and frequency domain , 2009 .

[3]  Wayne Johnson,et al.  Rotor Design for Whirl Flutter: An Examination of Options for Improving Tiltrotor Aeroelastic Stability Margins , 1999 .

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

[5]  R. G. Kvaternik,et al.  An experimental and analytical investigation of proprotor whirl flutter , 1977 .

[6]  Carlos E. S. Cesnik,et al.  On the modeling of integrally actuated helicopter blades , 2001 .

[7]  Farhan Gandhi,et al.  Design Optimization for Improved Soft In-Plane Tiltrotor Aeroelastic in Airplane Mode , 2010 .

[8]  W. Keats Wilkie,et al.  Design and Manufacturing of a Model-scale Active Twist Rotor Prototype Blade , 2008 .

[9]  Jai Moo Kim,et al.  Design optimization framework for tiltrotor composite wings considering whirl flutter stability , 2010 .

[10]  W. Earl Hall,et al.  Prop‐Rotor Stability at High Advance Ratios , 1966 .

[11]  Garret N. Vanderplaats,et al.  Numerical optimization techniques for engineering design , 1999 .

[12]  Peter R. Nelson,et al.  Response Surface Methods , 2003 .

[13]  C. W. Acree.  Effects of Rotor Design Variations on Tiltrotor Whirl-Mode Stability , 2001 .

[14]  B. J. Solak.  The Influence of Lightning and Static Electricity on Helicopter Design , 1966 .

[15]  Eric L. Hathaway,et al.  ACTIVE AND PASSIVE TECHNIQUES FOR TILTROTOR AEROELASTIC STABILITY AUGMENTATION , 2005 .

[16]  김태성.  Aeroelastic stability analysis of tiltrotor aircrafts with unsteady aerodynamic effect , 2009 .

[17]  SangJoon Shin,et al.  Influence of Geometric Coupling on the Whirl Flutter Stability in Tiltrotor Aircraft with Unsteady Aerodynamics , 2012 .

[18]  SangJoon Shin,et al.  Advanced Analysis on Tiltrotor Aircraft Flutter Stability, Including Unsteady Aerodynamics , 2008 .

[19]  Taeseong Kim,et al.  Structural Integrity Design of a Composite Wing in a Tiltrotor Aircraft , 2011 .

[20]  C. W. Acree,et al.  Rotor Design Options for Improving V-22 Whirl-Mode Stability , 2001 .

[21]  C. W. Acree,et al.  Rotor Design Options for Improving XV-15 Whirl-Flutter Stability Margins , 2004 .

[22]  Douglas C. Montgomery,et al.  Response Surface Methodology: Process and Product Optimization Using Designed Experiments , 1995 .

[23]  W Nixon Mark,et al.  Aeroelastic Response and Stability of Tiltrotors with Elastically-Coupled Composite Rotor Blades , 1993 .

[24]  Wayne Johnson,et al.  Technology Drivers in the Development of CAMRAD II , 1999 .

[25]  D. C. Dugan,et al.  The History of the XV-15 Tilt Rotor Research Aircraft: From Concept to Flight , 2001 .

[26]  William P. Gardiner,et al.  11 – Response Surface Methods , 1998 .

[27]  W. Johnson,et al.  Analytical model for tilting proprotor aircraft dynamics, including blade torsion and coupled bending modes, and conversion mode operation , 1974 .

[28]  Bernard Grossman,et al.  Polynomial Response Surface Approximations for the Multidisciplinary Design Optimization of a High Speed Civil Transport , 2001 .

[29]  J. H. Starnes,et al.  Construction of Response Surface Approximations for Design Optimization , 1998 .

[30]  W. Johnson,et al.  Dynamics of tilting proprotor aircraft in cruise flight , 1974 .

[31]  Carlos E. S. Cesnik,et al.  Cross-sectional analysis of nonhomogeneous anisotropic active slender structures , 2005 .

[32]  Yves Gourinat,et al.  A numerical study on active control for tiltrotor whirl flutter stability augmentation , 2006 .

[33]  Mark W. Nixon,et al.  Parametric Studies for Tiltrotor Aeroelastic Stability in Highspeed Flight , 1993 .

[34]  W. Johnson,et al.  Analytical modeling requirements for tilting proprotor aircraft dynamics , 1975 .

[35]  W Nixon Mark,et al.  An Experimental Evaluation of Generalized Predictive Control for Tiltrotor Aeroelastic Stability Augmentation in Airplane Mode of Flight , 2001 .

[36]  Mark W. Nixon,et al.  Aeroelastic response and stability of tiltrotors with elastically-coupled composite rotor blades. Ph.D. Thesis , 1993 .

[37]  John Liu,et al.  High-Speed Tiltrotors: Dynamics Methodology , 1993 .