Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 71 for “"piezoelectric actuators"”.
-
Piezoelectric actuators for helicopter rotor control
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1989.
-
Large-strain piezoelectric actuators using controlled structural buckling
… beam. This thesis presents a novel large-strain piezoelectric actuator exploiting the buckling of a structure with imbedded piezoelectric stack actuators. The realization of this buckling actuator began by rethinking the paradigm of where PZT stacks are placed in traditional flexure-based …
-
Power amplification for piezoelectric actuators in controlled structures
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1995.
-
Deformation and Force Characteristics of Laminated Piezoelectric Actuators
… the mechanical characteristics of laminated piezoelectric actuators that are manufactured at an elevated temperature, to cure the adhesive bonding the layers together, or to cure the layers made of polymeric composite material, and then cooled to a service temperature. Mainly discussed are …
-
Discrete Modeling and Sliding Mode Control of Piezoelectric Actuators
… with a resolution down to sub-nanometers, piezoelectric actuators (PEAs) have found wide applications in various nano-positioning systems. However, existence of various effects in PEAs, such as hysteresis and creep, as well as dynamics can seriously degrade the PEA performance or even lead …
-
On an Accelerated Fatigue -Testing Technique Using Piezoelectric Actuators
Furthermore, our results showed that repeated non-180° domain switching and phase transition alone did not result in ferroelectric fatigue. Rather, this fatigue is more likely due to electric charge accumulations at grain boundaries induced by repeated 180° domain switching.
-
Active microgravity vibration isolation using PVDF polymer piezoelectric actuators
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1991.
-
Construction and characterization of removable and reusable piezoelectric actuators
Piezoelectric patch-type actuators are being considered for use in acoustic control and vibration control of complex mechanical structures such as aircraft fuselages and automobile interiors. For complex structures, it is often difficult to predict the best location of actuator-structure …
-
Dynamic response of simply supported beams excited by piezoelectric actuators
The use of piezoelectric devices for the purposes of active noise or vibration control has become attractive in recent times. These small, power to weight efficient devices have had some success in active vibration control; however, the force transfer mechanism by which they interact with the …
-
Design and control of a robotic thumb using piezoelectric actuators
… systems, the use of large, heavy, and stiff actuators can also contribute to dexterity problems. If we expect robotic hands to interact with humans and human objects, joint actuators must allow a compromise of strength and compliance. Piezoelectric (PZT) actuators exhibit a high back …
-
Modeling of multiple layered piezoelectric actuators in active structural control
… finite length, multiple layered, induced strain actuators is investigated. A model of an arbitrary multiple layered actuator is utilized to predict the applied force and moment from the i<sup>th</sup> layer onto a structure. The transverse equations of motion of a simply supported beam are …
-
Power factor correction and power consumption characterization of piezoelectric actuators
… conventional amplifiers are used to drive these actuators, the current and voltage is close to 90 degrees out of phase. This causes the power factor (PF) of the load to be close to zero and results in excessive power requirements. This thesis reports the results of a study of the following …
-
Modelling and Evaluation of Piezoelectric Actuators for Wearable Neck Rehabilitation Devices
… they are limited by the use of conventional actuators. An overlooked type of actuation technology is that of piezoelectric actuators, more specifically, travelling wave ultrasonic motors (TWUM). In this work, a clear procedure that outlines how the required parameters within the hybrid TWUM …
-
An Examination of the ThermopiezoelectricEffect in Piezoelectric Actuators Via Finite Elements
The application of piezoelectric actuators in smart structures is a rapidly developing field, especially in aerospace environments. Since thermal effects play an important role in aerospace environments, thermopiezoelectricity has been studied as it takes into account the thermal field in addition …
-
Torsional and flexural control of sandwich composite beams with piezoelectric actuators
… sandwich beams subjected to loads induced by piezoelectric (PZT) actuators. The model was derived using Reddy's (1984) displacement field for a laminated plate which consists of cubic variation of the in-plane displacement through the thickness. In this model, beam deformations include …
-
Large gain amplification mechanism for piezoelectric actuators utilizing a rolling contact joint
Due to the limited displacement of piezoelectric stack actuators, common practice is to use some form of displacement amplification mechanism. An efficient, heavy-duty displacement amplification mechanism for piezoelectric stack actuators is presented in this thesis. The displacement amplification …
-
Active control of sound transmission/radiation from elastic plates using multiple piezoelectric actuators
… radiation from elastic plates with the use of piezoelectric transducers as actuators. A strain-energy model (SEM), based upon the conservation of strain energy, for a laminate beam with attached or embedded finite-length spatially distributed induced strain actuators was first developed to …
-
Use of Piezoelectric Actuators to Effect Snap-Through Behavior of Unsymmetric Composite Laminates
… new concept for morphing structures, the use of piezoelectric actuators to effect snap-through behavior of simple unsymmetric cross-ply composite laminates is examined. Many unsymmetric laminates have more than one stable room-temperature shape and can be snapped through from one stable shape to …
-
Active control of interior noise using piezoelectric actuators in a large-scale composite fuselage model
… studied. The control inputs are due to piezoelectric actuators bonded to the cylinder wall while error information from the interior acoustic field is sensed by microphones. A preliminary analytical development was conducted to investigate the mechanisms of the structural/acoustic …
-
Vibration Analysis and Control of an Inflatable Toroidal Satellite Component Using Piezoelectric Actuators and Sensors
… must be controlled while keeping the weight low. Piezoelectric materials have become strong candidates for actuator and sensor applications in the active vibration control of such structures due to their lightweight, conformability to the host structure, and distributed nature. In this study, our …
Page 1 of 4