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 66 for “"piezoceramic"”.
-
Deformations of Piezoceramic-Composite Actuators
In the past few years a new class of layered piezoceramic and piezoceramic-composite actuators, known as RAINBOW and GRAPHBOW, respectively, that are capable of achieving 100 times greater out-of-plane displacements than previously available has been developed. Prior to the development of RAINBOW …
-
Innovation in Piezoceramic Based Structural Health Monitoring
… The versatile functions and low cost of piezoceramic material has demonstrated its capability as transducers in structural health monitoring. This dissertation investigated modeling and innovative applications using piezoceramic based smart aggregate transducers for health monitoring of …
-
Optimum Damping of Beam Vibrations Using Piezoceramic Transducers
In this thesis a piezo-electro-mechanical system, constituted of an aluminum beam with five piezoelectric patches glued on it, each of them shunted with an RL electrical circuit, has been numerically and experimentally investigated, in order to determine the optimal electric tuning parameters for …
-
Piezoceramic Actuated Transducers for Interior Acoustic Noise Control
… of three thin flexures that are actuated by piezoceramic material attached to both sides. The flexures actuate a speaker cone that is attached to the end of the flexures. The transducer can act as a sensor or an actuator due to the nature of the piezoceramics. The sound absorbing transducer …
-
Nonlinear Mechanical and Actuation Characterization of Piezoceramic Fiber Composites
… variety of applications. However, actuators with piezoceramic fibers and interdigitated electrodes have risen to the forefront of the intelligent structures community due to their increased actuation capability. However, their fiber-reinforced construction causes them to exhibit anisotropic …
-
Piezoceramic induced strain actuation of one- and two-dimensional structures
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1989.
-
Induced strain of actuation of surface bonded and embedded piezoceramic patches
… flat plates by surface bonded and embedded piezoceramic patches was investigated. The free piezoceramic patch voltage/strain response was characterized using moire interferometry and Twyman-Green interferometry techniques. Moire interferometry experiments were conducted to investigate the …
-
The effects of shaped piezoceramic actuators on the excitation of beams
The effect of the shape of piezoceramic actuators on the vibration response of a simply supported beam is investigated. An equation is derived to convert between the shape of the piezoceramic actuator and the resulting moment distribution caused on the structure. A beam simulation program is then …
-
Low noise techniques applied to a piezoceramic receiver for gas coupled ultrasonic flaw detection
Piezoelectric plate transducers are commonly used for the generation and detection of ultrasonic signals and have applications in, for example, non-destructive testing and medical imaging. A rigorous theoretical investigation of thermal noise in plate transducers has been undertaken with the aim of …
-
An experimental investigation of the harmonic excitation of simply supported plates with multiple surface-bonded piezoceramic actuators
… is performed experimentally using arrays of piezoceramic patch pair actuators bonded to the plate surface. The experimental techniques used are presented, and the effects of patch location, relative actuator phasing, and excitation frequency on modal excitation are demonstrated. In addition, …
-
Enhancement of the Dynamic Buckling Load and Analysis of Active Constrained Layer Damping with Extension and Shear Mode Piezoceramic Actuators
… square plate sandwiched between two piezoceramic (PZT) layers. Points on the four edges of the bottom surface of the plate are restrained from moving vertically. The two opposite edges of the plate are loaded by equal in-plane compressive loads that increase linearly with time and the …
-
Power factor correction and power consumption characterization of piezoelectric actuators
A piezoceramic actuator used for structural control behaves electrically as a nearly pure capacitance. When 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 …
-
Strain transducers for active control
… vibration control using velocity feedback with piezoceramic actuator(s) and closely located velocity sensor(s). The first part of the thesis presents modeling and design studies for a square piezoceramic actuator used to implement a single channel velocity feedback control with a velocity sensor …
-
Ultrasonic spectroscopy of liquid filled piezoelectric tube
… be measured, thus minimally influencing flow. A piezoceramic tube was studied in an attempt to produce a sensor to encompass exactly those aims. Spectra were taken of liquid-filled piezoceramic tubes. Severalmodels for this system, both for the piezoceramic tube and the liquid within it, were …
-
Development of a system to measure marine turbulence
… shear in the ocean. The airfoil probe with it's piezoceramic beam encapsulated in a rubber airfoil has the simplest electronic processing system. However, the beam is very fragile and displays unpredictable thermal effects. An airfoil probe with semiconductor strain gauges on an aluminium …
-
Application of distributed measurements for finite element model verification
… by a distributed force (from a single or pair of piezoceramic actuators). The analytical results are obtained from the forced response analysis of a finite element model. A known piezoelectric actuator model that shows the actuation effects produced by symmetrically bonded actuators are line …
-
A demonstration of useful electric energy generation from piezoceramics in a shoe
… conditioning the electric energy harnessed by a piezoceramic source imbedded in a shoe insole. Two off-line, dc-dc direct converter hybrids (buck and forward) are proposed and implemented to improve the conversion efficiency over previously demonstrated conditioning schemes. A rigid, bimorph …
-
Investigation of a compact acoustic source array for the active control of aircraft engine fan noise
… of a sinusoidally varying voltage to a piezoceramic actuator bonded to them. The finite element method was used as a design tool to size the panel based on desired vibration characteristics. A boundary element acoustic analysis was used to predict the acoustic output from various …
-
AN INVESTIGATION OF NOVEL HIGH-SPEED ACTUATORS FOR SOFT PRODUCT ASSEMBLY AND MANIPULATION
… The final form of actuation considered was a piezoceramic bimorph. Similar in principle to the magnetostrictive material the piezoceramic bimorph deflects due to an applied voltage. The bandwidth of the bimorph is high and the relative cost of the material low. From the results of simulation …
-
Analytical Models to Predict Power Harvesting with Piezoelectric Materials
With piezoceramic materials, it is possible to harvest power from vibrating structures. It has been proven that micro- to milliwatts of power can be generated from vibrating systems. We develop definitive, analytical models to predict the power generated from a cantilever beam and cantilever plate. …
Page 1 of 4