Due to its high flexibility and enhanced electro-mechanical coupling, macro fiber composite (MFC) is widely used in the area of sensing, vibration control and structural control. While in application, MFCs are subjected to continuous cyclic mechanical load which may lead to the deterioration of piezoelectric coupling coefficient, thereby affecting its sensing performance. In order to predict the life cycle of MFC (d31 &amp; d31 type) subjected to mechanical loading, an experimental setup has been devised and the tests are carried out for various loading conditions. For lowering the effort and cost involved in the experiments, a non-linear finite element model along with cumulative damage theory is introduced. The degradation in the piezoelectric coupling coefficient obtained using the current theoretical model are in good comparison with the experimental observations. The current non-linear FE model is also extended to predict the stiffnesses and strengths of the MFC as a function of fatigue cycles. © 2017 Elsevier Ltd

Arunachalakasi Arockiarajan

Department of Applied Mechanics

Akash Pandey

Electrooptical effects

Fatigue damage

Fatigue of materials

Life cycle

Piezoelectricity

Structural dynamics

Vibrations (mechanical)

CUMULATIVE DAMAGE THEORIES

CURRENT THEORETICAL MODELS

Damage

Experimental approaches

MACRO FIBER COMPOSITE

Non-linear finite element model

NON-LINEAR FINITE ELEMENTS

PIEZOELECTRIC COUPLINGS

finite element method

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Composite Structures

This letter explores the benefits offered by an asymmetric monostable potential function over the conventional symmetric linear and bistable potential functions in broadband vibration energy harvesting. Multi-stable harvesters such as the bistable and tristable harvesters provide an order of magnitude higher power than the linear harvesters while undergoing inter-well oscillations. However, when the excitation noise levels are insufficient to trigger inter-well oscillations, such harvesters provide very low power output. We propose a monostable configuration with an asymmetric potential energy function that is capable of providing a high energy output starting from excitation levels as low as 0.005 g2/Hz (g denotes acceleration due to gravity). The superior performance of the proposed asymmetric configuration over the conventional linear and bistable configurations is demonstrated through experiments, considering a band-limited white noise excitation. The experimental results also indicate that the asymmetric configuration delivers higher power at lower strain levels than the bistable configuration, mitigating the burden on the piezoelectric transducer. Thus, the asymmetric configuration offers a two-fold advantage in energy harvesting, leading to an increase in both the power output and the lifetime of the piezoelectric transducer. © 2018 Author(s).

Fulltext

Applied Physics Letters

Exploring the benefits of an asymmetric monostable potential function in broadband vibration energy harvesting

Macro fiber composite (MFC) is extensively used in vibration control and actuation applications due to its high flexibility and enhanced coupling coefficients. During these applications, MFCs are subjected to the continuous cyclic electrical loading, which may lead to the degradation in its actuation performance. In order to predict the life cycle of MFCs, an experimental setup has been devised and experiments are performed under cyclic loading condition. Efforts involved in the experiments are huge in terms of time and cost. Hence, an attempt has been made to develop a theoretical model to predict the fatigue behavior of MFCs. A nonlinear finite element method has been formulated based on Kirchhoff plate theory wherein the fatigue failure criterion based on strain energy is embedded. Simulated results based on the proposed model is compared with experimental observation and are in good agreement with each other. Variation in the life cycle of MFCs are also studied for different operating temperatures as well as structural/geometric configurations. © 2017 IOP Publishing Ltd.

Smart Materials and Structures

Fatigue study on the actuation performance of macro fiber composite (MFC): Theoretical and experimental approach

1-3 type piezocomposites are very attractive materials for transducers and biomedical application, due to its high electromechanical coupling effects. Reliability study on 1-3 piezocomposites subjected to cyclic loading condition in transducer application is one of the primary concern. Hence, this study focuses on 1-3 piezocomposites for various PZT5A1 fiber volume fraction subjected to electrical fatigue loading up-to 106 cycles and at various elevated temperature. Initially experiments are performed on 1-3 piezocomposites, in order to understand the degradation phenomena due to various range in amplitude of electric fields (unipolar &amp; bipolar), frequency of applied electric field and for various ambient temperature. Performing experiments for high cycle fatigue and for different fiber volume fraction of PZT5A1 is a time consuming process. Hence, a simplified macroscopic uni-axial model based on physical mechanisms of domain switching and continuum damage mechanics has been developed to predict the non-linear fatigue behaviour of 1-3 piezocomposites for temperature dependent electrical fatigue loading conditions. In this model, damage effects namely domain pinning, frozen domains and micro cracks, are considered as a damage variable (ω). Remnant variables and material properties are considered as a function of internal damage variable and the growth of the damage is derived empirically based on the experimental observation to predict the macroscopic changes in the properties. The measured material properties and dielectric hysteresis (electric displacement vs. electric field) as well as butterfly curves (longitudinal strain vs. electric field) are compared with the simulated results. It is observed that variation in amplitude of bipolar electric field and temperature has a strong influence on the response of 1-3 piezocomposites. © 2016 Author(s).

AIP Advances

Experimental and theoretical investigation of temperature-dependent electrical fatigue studies on 1-3 type piezocomposites

The effective thermo-electro-elastic properties of Macro-Fiber Composites (MFC) are evaluated by means of an analytical model based on 'equivalent layered approach' using the concepts of 'rule of mixtures' and 'series and parallel capacitance theory'. To account for the complex electric field distribution and the constituents shape and position, a numerical model based on finite element calculations is developed using 'unit-cell approach'. The piezoelectric charge constants of MFCs are experimentally evaluated by applying electrical load in various thermal environment (27. °C to 70. °C). The proposed models are validated with the results available in literature, experimental values and the data from the manufacturer. Also, effect of thermal environment on the effective constants of MFCs for various volume fraction of piezoceramic phase is investigated. © 2014 Elsevier Ltd.

Experimental and theoretical investigation on the thermo-electro-elastic properties of Macro-Fiber Composites (MFC)

Effect of waviness and orientation of carbon nanotubes on random apparent material properties and RVE size of CNT reinforced composites

Sensors and Actuators A: Physical

Experimental investigation of performance reliability of macro fiber composite for piezoelectric energy harvesting applications

Fatigue study on the sensor performance of macro fiber composite (MFC): Theoretical and experimental approach

Journal	Data powered by TypesetComposite Structures
Publisher	Data powered by TypesetElsevier Ltd
ISSN	02638223
Open Access	No