Analysis Of Piezoelectric Actuator Research Articles

Hysteresis modeling and analysis of piezoelectric actuators using a modified LuGre model at different preloads and frequencies

Despite a large of models proposed to characterize the nonlinear hysteresis of piezoelectric actuators, few of them can show the effects of different preloads on the nonlinear hysteresis. In this paper, a modified LuGre model (MLM) is presented for piezoelectric actuators under different preloads to accurately characterize its dynamic hysteresis nonlinearity at different frequencies. Based on the classical LuGre model (CLM), the presented model introduces infinite impulse response filters and smoothness coefficient to simplify it. The parameters of the models were identified by the non-linear least squares method. A series of experiments were conducted to verify the validity of the MLM under different preloads at different frequencies excitation signals.In the constant frequency experiments under different preloads, the MLM reduces the mean error by 68.1%−81.9% compared with the CLM; In the constant preload experiments at different frequencies, the MLM reduces the mean error by 72.2%−83.0% and 65.9%−83.2% compared with the classical Bouc–Wen model (CBM) and the CLM.

Fatigue analysis of piezo composite disc for energy harvesting

Electrical energy is highly required for operating the electrical, electronics, mechanical, computer instruments both at micro and macro levels. This energy can be generated in macro level by using wind, waves, sun light etc and in micro level by using electro static, electromagnetic and vibration energy. In micro level, the power density is very high for vibration energy using piezo electric disc type actuators. Under vibrations, the energy harvester can be damaged by cyclic loads. Fatigue analysis is required to increase the life span of the piezo electric actuators. In this paper, therefore, it is presented that the fatigue analysis of piezo electric actuators to observe the operating loads. The limited stress should not be more than 3.38 MPa.

Modelling and analysis of piezoelectric actuators with partially debonded adhesive layers

In the modelling of thin-sheet piezoelectric actuators, the bonding condition between the actuator and the host structure can place a significant influence on the behaviour of the actuator. This paper provides a comprehensive theoretical study of the electromechanical behaviour of a thin-sheet piezoelectric actuator bonded to a host structure through a partially debonded adhesive layer under in-plane electric loading. The focus is on the coupled effect of the debonding and adhesive layer on the interfacial stress. The piezoelectric actuator is characterized by a general electro-elastic Euler–Bernoulli beam model featuring both axial and bending deformation. The theoretical solution of the problem is formulated by using singular integral equations, in terms of the interfacial shear and normal stresses, which are solved by using Chebyshev polynomials. The introduction of the adhesive layer in the model changes the singular behaviour of the problem. The current singular integral equations are shown to be effective in solving for both singular and non-singular stresses. Typical examples have been provided to show the effect of the geometry and the material property on the local stress field along the interface.

Model and Analysis of Piezoelectric Actuator in Practical Three-Stage Mechanism

Piezoelectric elements (PEMs) are used in a variety of applications. In this paper we developed a full analytical model of a piezoelectric actuator which includes piezostack elements and a three-stage amplification mechanism. The model was derived separately for each unit of the system. Next, the units were combined, while taking into account their coupling. The hysteresis phenomenon, which is significant in piezoelectric materials, was extensively described. A number of hysteresis calculating algorithms were investigated and a new simple method of examining piezoelectric hysteresis was demonstrated. The theoretical model was verified in a laboratory setup. This setup includes a piezoelectric actuator, measuring devices and an acquisition system. The measured results were compared to the theoretical results, while taking into account the nonlinear phenomena of the piezoelectric materials and the three-stage amplification mechanism, and were found to be very similar. Due to its simplicity, this model can easily be modified in order to be applied to other PEMs or other amplification mechanism methods. The main novelty of this work lies in its system-level approach for piezoelectric actuators. All of the system elements include non-linear phenomena, which mutually influence each other. First, each part of the system will be described separately and then, the combined subsystems and the coupling between their parts will be represented. Finally we treat this system as one whole unit.

Characterization and Mathematical Modelling of Geometric Effects on Piezoelectric Actuators

This paper focuses on the characterization and static structural analysis of piezoelectric actuator to investigate the sequential increasing effect of piezoelectric patches. The effect on the tip deflection is observed analytically, numerically and experimentally. By varying the quantity and the geometry of piezoelectric patches/beams, the actuation effect is analyzed. A mathematical model has been developed for the unequal lengths of patches and beam. The analysis is carried out numerically to examine the tip deflection under various parameters. The results are analyzed and verified experimentally. The results are found to be in accordance with the analytical and numerical results. This permits the desired configuration of an actuator in applications like hydraulic valves for actuating and controlling the flow of liquid as per need.

Large Effective-Strain Piezoelectric Actuators Using Nested Cellular Architecture With Exponential Strain Amplification Mechanisms

Design and analysis of piezoelectric actuators having over 20% effective strain using an exponential strain amplification mechanism are presented in this paper. Piezoelectric ceramic material, such as lead zirconate titanate (PZT), has large stress and bandwidth, but its extremely small strain, i.e., only 0.1%, has been a major bottleneck for broad applications. This paper presents a new strain amplification design, called a “nested rhombus” multilayer mechanism, that increases strain exponentially through its hierarchical cellular structure. This allows for over 20% effective strain. In order to design the whole actuator structure, not only the compliance of piezoelectric material but also the compliance of the amplification structures needs to be taken into account. This paper addresses how the output force and displacement are attenuated by the compliance involved in the strain amplification mechanism through kinematic and static analysis. An insightful lumped parameter model is proposed to quantify the performance degradation and facilitate design tradeoffs. A prototype-nested PZT cellular actuator that weighs only 15 g has produced 21% effective strain (2.5 mm displacement from 12-mm actuator length and 30 mm width) and 1.7 N blocking force.

Optimal energy density piezoelectric bending actuators

The design and analysis of piezoelectric actuators is rarely optimized for low mass applications. However, emerging technologies such as micro air vehicles, and microrobotics in general, demand high force, high displacement, low mass actuators. Utilization of generic piezoceramics and high performance composite materials coupled with intelligent use of geometry and novel driving techniques yields low cost, rapidly prototyped, ultra-high energy density bending actuators for use in such applications. The design is based upon a laminate plate theory model for a stacked multimorph cantilever actuator, encompassing all possible layups, layer anisotropies, internal and external excitations, and intrinsic and extrinsic geometries. Using these principles, we have fabricated 12 mg PZT bimorph actuators with greater than 2 J kg −1 energy density. This gives a performance increase of an order of magnitude or greater compared to existing commercially available piezoelectric bending actuators.

Modelling and analysis of piezoelectric actuators in anisotropic structures

In this paper, we examine the coupled electromechanical behaviour of a piezoceramic actuator bonded to a finite elastic medium under inplane mechanical and electric loading. The purpose of the current work is to study the suitability of using a simple actuator model to simulate the load transfer between actuators and the host medium. The actuator is characterized by an electroelastic line model with the poling direction being perpendicular to its length. The solution of this electromechanically couple problem is provided by solving singular integral equations in terms of an interfacial shear stress and conducting finite element analysis. The results show that the transfer of the actuation energy between the actuator and the host structure can be effectively simulated using the developed theoretical model. Typical examples are provided to show the effects of the geometry, the material combination and anisotropy upon the load transfer. The study is further extended to treat the interfacial debonding between the actuator and the host material.