PSI - Issue 23

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Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000 – 000 Structural Integrity Procedia 00 (2019) 000 – 000

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ScienceDirect

Procedia Structural Integrity 23 (2019) 535–540

© 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the ICMSMF organizers © 201 9 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the IC MSMF organizers. Abstract In this work, a special multilayer piezoelectric cantilever energy h rv ster with active piezo-el ctric and pr tective ceramic lay rs w s suggested and studied. Fracture mechanics behavior of such a layered structure was an lyzed by means of t nalytical model. Namely, the resist nce of the structure to pr pag tion of surfac cracks upon harmonic vibrations wa studied. The apparent fractur tou ness of the laminate (taking into account also thermal residual stres es induced from processi g) was calculated using the weight fu ction method. The maxim l allowable accelerati n of the beam´s cla ped end applied upon th give forcing frequ ncy and war nti g that the potential surface cracks will not propagate through the multilayer structure was determined for a suggested configuration of the energy harvester. © 201 9 The Authors. Published by Elsevier B.V. This is an ope acces article under CC BY-NC-ND lic nse (http://creativecommons org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the IC MSMF organizers. 9th International Conference on Materials Structure and Micromechanics of Fracture Crack propagation analysis in multilayer piezoelectric energy harvester Zdeněk Machů a , Zdeněk Majer a, * , Zdeněk Hadaš a , Oldřich Ševeček a a Brno University of Technology, Faculty of Mechanical Engineering, Technická 2896/2, 616 69 Brno, Czech Republic Abstract In this work, a special multilayer piezoelectric cantilever energy harvester with active piezo-electric and protective ceramic layers was suggested and studied. Fracture mechanics behavior of such a layered structure was analyzed by means of the analytical model. Namely, the resistance of the structure to propagation of surface cracks upon harmonic vibrations was studied. The apparent fracture toughness of the laminate (taking into account also thermal residual stresses induced from processing) was calculated using the weight function method. The maximal allowable acceleration of the beam´s clamped end applied upon the given forcing frequency and warranting that the potential surface cracks will not propagate through the multilayer structure was determined for a suggested configuration of the energy harvester. 9th International Conference on Materials Structure and Micromechanics of Fracture Crack propagation analysis in multilayer piezoelectric energy harvester Zdeněk Machů a , Zdeněk Majer a, * , Zdeněk Hadaš a , Oldřich Ševeček a a Brno University of Technology, Faculty of Mechanical Engineering, Technická 2896/2, 616 69 Brno, Czech Republic 1. Introduction Nowadays, the generation of electricity is addressed as one of the key challenges for the future. Besides the big energy sources, also small autonomous sources of electricity are required. One of them could be e.g. an energy harvester converting mechanical energy from vibrations into an electrical one. These systems seem to be very promising in terms of powering small devices (ultralow-power electronics, such as various sensors or autonomous 1. Introduction Nowadays, the generation of electricity is addressed as one of th key challenges for the f ture. Besides the big energy sources, also s all autonomous sources of electricity are required. O of th m could be .g. an nerg harvester converting mecha ical energy from vibrations into an electrical one. These y tems seem to be very promising in terms of powering small devices (ultralow-power electronics, such as various sensors or autonomous Keywords: crack; piezoelectricity; energy harvester; multilayer structure; R-curve; weight function. Keywords: crack; piezoelectricity; energy harvester; multilayer structure; R-curve; weight function.

* Corresponding author. Tel.: +420-54114-2857. E-mail address: majer@vutbr.cz * Correspon ing author. Tel.: +420-54114-2857. E-mail address: majer@vutbr.cz

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the IC MSMF organizers. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an ope acces article under CC BY-NC-ND lic nse (http://creativecommon org/licenses/by-nc-nd/4.0/)

Peer-review under responsibility of the scientific committee of the IC MSMF organizers.

2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the ICMSMF organizers 10.1016/j.prostr.2020.01.141