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Full-Text Articles in Engineering
Active Control Of Large Amplitude Nonlinear Free Vibrations And Nonlinear Supersonic Panel Flutter Of Beams And Composite Plates Using Piezoelectric Self-Sensing Actuators, Qinqin Li
Mechanical & Aerospace Engineering Theses & Dissertations
This thesis employs a coupled structural-electrical finite element modal formulation for the control of nonlinear free vibrations, and supersonic panel flutter of beams and composite plates with and without thermal environment. Multiple modes of the nonlinear free vibration and supersonic panel flutter are considered in the closed loop simulations. Two different controllers are designed and investigated. The first one is the output feedback controller comprised of a Linear Quadratic Regulator (LQR) and an Extended Kalman Filter (EKF). EKF considers the nonlinear state space matrix and has a gain sequence evaluated on-line. Thus the LQR/EKF nonlinear controller has more accurate state …
Shape Memory Alloy Applications On Control Of Thermal Buckling, Panel Flutter And Random Vibration Of Composite Panels, Xinyun Guo
Mechanical & Aerospace Engineering Theses & Dissertations
Shape Memory Alloy (SMA) has a unique ability to recover large prestrain (up to 8∼10% elongation for Nitinol, a typical SMA material) completely when the alloy is heated (e.g. aerodynamic heating) above the austenite finish temperature Af. An innovative concept is to utilize the large recovery stress by embedding the prestrained SMA in a traditional fiber-reinforced laminated composite plate, which is called SMA hybrid composite (SMAHC) plate. In this research, static thermal and aerothermal deflections, dynamic panel flutter and random response are investigated for traditional composite plates and SMAHC plates under combined aerodynamic, random and thermal loads by employing nonlinear …
Modeling Multilevel Supply Chain Systems To Optimize Order Quantities And Order Points Through Mathematical Models, Discrete Event Simulation And Physical Simulations, Alok K. Verma
Mechanical & Aerospace Engineering Theses & Dissertations
Managing supply chains in today's distributed manufacturing environment has become more complex. To remain competitive in today's global marketplace, organizations must streamline their supply chains. The practice of coordinating the design, procurement, flow of goods, services, information and finances, from raw material flows to parts supplier to manufacturer to distributor to retailer and finally to consumer requires synchronized planning and execution. Efficient and effective supply chain management assists an organization in getting the right goods and services to the place needed at the right time, in the proper quantity and at acceptable cost. Managing this process involves developing and overseeing …
Nonlinear Flutter Of Curved Panels Under Yawed Supersonic Flow Using Finite Elements, Mohamed Salim Azzouz
Nonlinear Flutter Of Curved Panels Under Yawed Supersonic Flow Using Finite Elements, Mohamed Salim Azzouz
Mechanical & Aerospace Engineering Theses & Dissertations
In the extensive published literature on panel flutter, a large number of papers are dedicated to investigation of flat plates in the supersonic flow regime. Very few authors have extended their work to flutter of curved panels. The curved geometry generates a pre-flutter behavior, triggering a static deflection due to a static aerodynamic load (SAL) over the panel as well as dynamic characteristics unique to this geometry. The purpose of this dissertation is to provide new insights in the subject of flutter of curved panels. Finite element frequency and time domain methods are developed to predict the pre/post flutter responses …