Recent Submissions

  • Control of a flexible wing with flaps using a set theoretic active-passive framework 

    Menon, Alok N.; Chakravarthy, Animesh; Gruenwald, Benjamin C.; Yucelen, Tansel (American Institute of Aeronautics and Astronautics Inc., 2019-01-06)
    This paper develops a distributed parameter model for a multiple component structure morphing, flexible wing aircraft with a n trailing edge rigid flaps. Using a set-theoretic adaptive control approach that utilizes ...
  • Simulated flight testing of an adaptive loss-of-control avoidance pilot advisory display 

    Rafi, Melvin; Rajaram, Kiran; Moustafa, Mohamed A.; Bin Salmaan Hussain, Danial Imran; Morales, Kevin; Steck, James E.; He, Jibo; Chakravarthy, Animesh (American Institute of Aeronautics and Astronautics Inc., 2019-01-06)
    Loss-of-Control has been consistently deemed the primary contributor to air accidents globally. Systems capable of alerting pilots when impending control loss is predicted to occur have the potential to promote safer flight. ...
  • Retrofit winglets for wind turbines 

    Matheswaran, Vijay; Miller, Leonard Scott; Moriarty, Patrick J. (American Institute of Aeronautics and Astronautics Inc., 2019-01-06)
    The benefits of using winglets on wind turbines has been well documented. However, adding winglets to wind turbine blades leads to significant increases in blade root bending moments, requiring expensive structural ...
  • Machine learning applied to programming quantum computers 

    Steck, James E.; Behrman, Elizabeth C.; Thompson, Nathan (American Institute of Aeronautics and Astronautics, 2019-01-06)
    We apply machine learning to “program” quantum computers, both in simulation and in experimental hardware. A major difficulty in quantum computing is developing effective algorithms that can be programmed on a quantum ...
  • Real-time adaptive prediction of loss-of-control margins on a fourth order aircraft 

    Rafi, Melvin; Steck, James E.; Chakravarthy, Animesh (American Institute of Aeronautics and Astronautics Inc., 2019-01-06)
    Loss-of-Control events continue to be the most significant contributing factor to air accidents worldwide. Predictive systems capable of warning pilots of impending entry into control loss have the potential to further ...
  • Design, implementation and experimental testing of an inertial sensor system to quantify wing deflection 

    Schirmer, Georg; Steck, James E.; Chakravarthy, Animesh (American Institute of Aeronautics and Astronautics Inc., 2019-01-06)
    This research investigates a novel approach of using inertial micro-electromechanical sensors in combination with a Kalman state estimator to quantify wing deflection of a highly flexible morphing wing. Motivated by NASA’s ...
  • Adaptive control system for flapping wing aircraft: A gain study on optimal control modification 

    Chandrasekaran, Balaji K.; Steck, James E. (American Institute of Aeronautics and Astronautics, Inc., 2019-01-06)
    Prior work developed a model for a bird-like flapping wing aircraft using Modified strip theory for aerodynamics, a flight dynamics model based on Newtonian equations and an adaptive flight controller. This model was ...
  • Trajectory prediction using coupled cfd-rbd with dynamic meshing 

    Sathyanarayana, Nidhi D.; Hoffmann, Klaus A. (American Institute of Aeronautics and Astronautics, Inc., 2019-01-06)
    Debris released post bird impact can cause secondary damage to downwind airplane surfaces. The debris is simplified in geometry and represented as a flat plate. A coupled CFD-RBD solver with dynamic meshing is used for ...
  • Effect of data filtering on flight loads spectra 

    Rokhsaz, Kamran; Kliment, Linda K. (American Institute of Aeronautics and Astronautics, 2019-06-14)
    Operational data from 27.4 hours of aerial firefighting and ferry missions are used to examine the effect of various filters at removing the structural modes from the data and the corresponding effect on flight loads ...
  • Higher-order estimations of load factor from derived gust velocity 

    Rokhsaz, Kamran; Kliment, Linda K. (American Institute of Aeronautics and Astronautics, Inc., 2018-11-12)
    Pratt's formula, in which the aircraft is modeled as a single-degree-of-freedom system, is used extensively to extract derived gust velocities from measured normal acceleration. There is evidence that airframe mass ...
  • Stress model of composite pipe joints under bending 

    Yang, Chihdar Charles; Huang, Hai; Guan, Zhidong (SAGE Publications, 2002-06)
    Recently, composite pipe is becoming popular in the offshore oil and gas industry due to the new floating designs of various platforms which have made deepwater oil and gas exploration and production more economical and ...
  • A semi-analytical method for determining the strain energy release rate of cracks in adhesively-bonded single-lap composite joints 

    Yang, Chihdar Charles; Sun, Wenjun; Tomblin, John S.; Smeltzer, Stanley S., III (SAGE Publications, 2007-07)
    A semi-analytical method for determining the strain energy release rates due to a prescribed crack in an adhesively-bonded, single-lap composite joint subjected to axial tension is presented. The field equations in terms ...
  • Thermally induced loads of fastened hybrid composite/aluminum structures 

    Yang, Chihdar Charles; Sun, Wenjun; Seneviratne, Waruna; Shashidhar, Ananthram K. (American Institute of Aeronautics and Astronautics, 2008-03)
    Large composite structures have been increasingly used in the aviation industry. New applications of composite materials include primary structures such as aircraft fuselages. These large composite parts are sometimes ...
  • Evaluation and adjustments for ASTM D 5656 standard test method for thick-adherend metal lap-shear joints for determination of the stress-strain behavior of adhesives in shear by tension loading 

    Yang, Chihdar Charles; Huang, Hai; Tomblin, John S.; Oplinger, D.W (American Society for Testing and Materials, 2001-01)
    Adhesive-bonded joints have been used widely for composite materials as a necessary alternative to conventional mechanical joint designs. In a bonded joint, the load is transferred from one substrate to the other mainly ...
  • Characterization of bondline thickness effects in adhesive joints 

    Tomblin, John S.; Harter, P.; Seneviratne, Waruna; Yang, Chihdar Charles (American Society for Testing and Materials, 2002-04)
    Growing application of composite materials in air-frame structures tends to make significant use of bonded constructions. Despite the large work that has been done on adhesive characterization over previous years, various ...
  • Stress analysis of composite pipe joints under combined torsional and tensile loading 

    Yang, Chihdar Charles; Guan, Zhidong (American Society of Mechanical Engineers (ASME), 2009-09)
    An analytical model was developed using the first-order laminated shell theory to determine stress and strain distributions within a composite pipe joint under combined torsional and tensile loading. Due to the axisymmetric ...
  • Elastic-plastic model of adhesive-bonded single-lap composite joints 

    Yang, Chihdar Charles; Huang, Hai; Tomblin, John S.; Sun, Wenjun (SAGE Publications, 2004-02)
    An analytical model for determining adhesive stress distributions within the adhesive-bonded single-lap composite joints was developed. ASTM D3165 Strength Properties of Adhesives in Shear by Tension Loading of SingleLap-Joint ...
  • Low-velocity impact and damage process of composite laminates 

    Guan, Zhidong; Yang, Chihdar Charles (SAGE Publications, 2002-04)
    Several important issues regarding damage simulation of composite laminates due to low velocity impact were investigated including contact law, damage initiation and the corresponding change of stiffness, and damping. ...
  • Strain energy release rate analysis of adhesive-bonded composite joints with a prescribed interlaminar crack 

    Chadegani, Alireza; Yang, Chihdar Charles; Dan-Jumbo, Eugene (American Institute of Aeronautics and Astronautics, 2009-01)
    Delamination is among the critical failure modes in fiber-reinforced laminated composite structures. This paper presents an analytical approach by taking into account the first-ply failure in adhesive-bonded composite ...
  • Stress and failure analyses of adhesive-bonded composite joints using ASTM D3165 specimens 

    Huang, Hai; Yang, Chihdar Charles; Tomblin, John S.; Harter, P. (American Society for Testing and Materials, 2002-04)
    An analytical model was developed to determine the stress and strain distributions of single-lap adhesive-bonded composite joints under tension. Both the adherend and the adhesive were assumed linear elastic in the ...

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