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Author

Y. Mohan

Other affiliations: University of Arkansas
Bio: Y. Mohan is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Piezoelectricity & Dielectric. The author has an hindex of 2, co-authored 3 publications receiving 27 citations. Previous affiliations of Y. Mohan include University of Arkansas.

Papers
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Journal ArticleDOI
TL;DR: In this article, the grain size has significant effects on the electromechanical response of piezoceramics and the effect of grain size on the hysteresis, fatigue and creep response are analyzed.

30 citations

Journal ArticleDOI
TL;DR: In this paper, a simplified macroscopic uni-axial model based on physical mechanisms of domain switching and continuum damage mechanics has been developed to predict the nonlinear fatigue behavior of 1-3 piezocomposites for temperature dependent electrical fatigue loading conditions.
Abstract: 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 & 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.

11 citations

Proceedings ArticleDOI
TL;DR: In this paper, a uni-axial micro-mechanical model is developed to predict the fatigue behavior of 1-3 piezocomposite for various fiber volume fraction subjected to cyclic electric field up to 10 6 cycles.
Abstract: 1-3 piezocomposites are very attractive materials in underwater and biomedical applications. These materials may be subjected to high electric field (2kV/mm) under continuous operation leading to deterioration in the output parameters such as remnant, saturation polarization and strain. Hence in this work, an experimental study is carried out to understand the fatigue behavior of 1-3 piezocomposites for various fiber volume fraction subjected to cyclic electric field (2kV/mm, 50Hz) up to 10 6 cycles. A uni-axial micro-mechanical model is developed to predict the fatigue behaviour of 1-3 piezocomposite. The novelty of this model is, the remnant polarization and strain are chosen as internal variables which is also dependent on the damage.The simulated results are compared with the experimental observations, it is observed that the proposed micro-mechanical model is able to predict the material degradation with increase in number of cycles of operation. A parametric study is also conducted for various fiber volume fraction of 1-3 piezocomposite as function of fatigue cycle it shows that the amplitude of dielectric hysteresis and butterfly loop decreases with increase in the number of cycles. The fatigue behavior has a substantial effect in the performance parameters such as coercive field, remnant polarization and the asymmetric strain behavior of 1-3 piezocomposite. This fatigue study explores the utilities of 1-3 piezocomposites in transducer applications by providing insight into the device design.

4 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, a low-frequency magnetic field sensor based on a composite multiferroic consisting of a bidomain lithium niobate/metglas laminate shaped in form of a tuning fork was presented.

32 citations

Journal ArticleDOI
TL;DR: In this article, the authors conducted nanoindentation experiments on polycrystalline PMN-PT (a relaxor ferroelectric material) with a focus to investigate the influence of domain configurations on the indentation size effect (ISE) in hardness.

31 citations

Journal ArticleDOI
TL;DR: In this article, the bipolar fatigue behaviors of lead magnesium niobate-lead zirconate titanate (PMN-PZT) ceramics sintered by conventional sintering (CS) and spark plasma sinterings (SPS) were systematically investigated.

24 citations

Journal ArticleDOI
TL;DR: In this paper, a review of the progress regarding the study of effective properties and nonlinearities in 1-3 piezocomposites in a coherent and holistic manner is presented.
Abstract: 1-3 piezocomposites are excellent candidate materials for sensor, actuator and transducer applications owing to their remarkable dielectric properties, enhanced piezoelectric coupling constants and improved hydrostatic performance along with tunable acoustic impedance, high bandwidth and reliability. These materials find extensive use in aerospace, naval and biomedical sectors. 1-3 piezocomposites show a linear response when subjected to low electric fields and/or mechanical stresses. In such cases, linear models are sufficient for predicting their linear response. But, when high electro-mechanical loads are applied to these materials, they show nonlinearity owing to the presence of a passive and viscoelastic polymer matrix phase and inherent hysteretic damping in the piezoceramic fibers. This is when it becomes mandatory to understand both their linear and nonlinear behavior under different magnitudes of thermo-electro-mechanical static and dynamic loads. Linear response is modeled using linear piezoelectric constitutive equations. Nonlinearities in the form of hysteresis, depolarization, fatigue and creep occurs in 1-3 piezocomposites, which drastically affects their accuracy, precision and efficiency. In order to understand these nonlinearities, analytical and numerical methods have been proposed by several researchers in the past. An endeavor has been undertaken to review some of the attempts made earlier in these directions. Effective properties of these inhomogeneous media are evaluated through different hypotheses and assumptions. Most often, experimental routes are undertaken to predict material properties of 1-3 piezocomposites; nevertheless, the experimental evaluation of a few material properties is quite difficult and sometimes impossible, even with the best state-of-the-art experimental facilities. This motivates researchers to develop theoretical models to predict these material properties. Nonlinearities in 1-3 piezocomposites have been studied by researchers earlier with different theoretical modeling approaches and experimental techniques. This review paper is an endeavor to discuss the progress regarding the study of effective properties and nonlinearities in 1-3 piezocomposites in a coherent and holistic manner.

17 citations