The research in this area is closely related to the previous research activity related to the modelling of cracks at the interface of layered composites using a new concept of linear fracture mechanics based on a combination of stress and energy fracture criteria (so called finite fracture mechanics) and the application of gradient elasticity, which allows capturing the size effect and removing singularities present in classical fracture mechanics. Closely related to the study of the response of cracks under conditions of gradient elasticity is the investigation of the response of cracks under conditions of flexoelectricity. Flexoelectricity is an electromechanical coupling between polarization and strain gradient, as opposed to piezoelectricity, which is a relationship between strain and electrical polarization. In addition to the flexoelectric phenomenon, attention is also paid to other functional properties of advanced material structures sometimes referred to as metamaterials. These may include, for example, auxetic structures, structures with negative thermal expansion or structures with tunable stiffness or dynamic characteristics. At the same time, Research Topic 2 follows up on Topic 3.

Projects

• GAČR 21-12994J (international CZ-TW): „Smart MEMS/NEMS resonators with functional material layers utilizing local and global nonlinearities for ultrasensitive (bio) sensing applications “, 2021-2023.

• GAČR 19-17457S: „Manufacturing and analysis of flexible piezoelectric layers for smart engineering “, 2020-2021.

• GAČR 17-08153S: „Novel material architectures for SMART piezoceramic electromechanical converters “,2017-2019.

• GAČR 101/09/1821: “Mechanical and fracture properties of multilayered ceramic/ceramic and ceramic/metal materials with graded layers”, 2009-2012.

Publications

MACHŮ, Z.; RUBEŠ, O.; ŠEVEČEK, O.; HADAŠ, Z. Experimentally Verified Analytical Models of Piezoelectric Cantilevers in Different Design Configurations. SENSORS, 2021, roč. 21, č. 20, s. 6759-6759. ISSN: 1424-8220.

HOFER, A.; WALTON, R.; ŠEVEČEK, O.; MESSING, G.; BERMEJO, R. Design of damage tolerant and crack-free layered ceramics with textured microstructure. Journal of the European Ceramic Society, 2020, roč. 2020, č. 40, s. 427-435. ISSN: 0955-2219.

MACHŮ, Z.; ŠEVEČEK, O.; HADAŠ, Z.; KOTOUL, M. Modelling of electromechanical response and fracture resistance of multilayer piezoelectric energy harvester with residual stresses. JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES, 2020, roč. 31, č. 19, s. 2261-2287. ISSN: 1530-8138.

ŠEVEČEK, O.; KOTOUL, M.; PROFANT, T.; HRSTKA, M. Crack kinking out of interface of two orthotropic materials under combined thermal/mechanical loading. Theoretical and Applied Fracture Mechanics, 2020, roč. 105, č. 1, s. 1-18. ISSN: 0167-8442.

TOFEL, P.; MACHŮ, Z.; CHLUP, Z.; HADRABA, H.; DRDLÍK, D.; ŠEVEČEK, O.; MAJER, Z.; HOLCMAN, V.; HADAŠ, Z. Novel layered architecture based on Al2O3/ZrO2/BaTiO3 for SMART piezoceramic electromechanical converters. European Physical Journal-Special Topics, 2019, roč. 228, č. 7, s. 1575-1588. ISSN: 1951-6355.

BOCCACCINI, D.; ŠEVEČEK, O.; FRANDSEN, H.; DLOUHÝ, I.; MOLIN, S.; HJELM, J.; CANNIO, M.; HENDRIKSEN, P. Determination of the bonding strength in solid oxide fuel cells’ interfaces by Schwickerath crack initiation test. Journal of the European Ceramic Society, 2017, roč. 2017, č. 37, s. 3565-3578. ISSN: 0955-2219.

ŠEVEČEK, O.; KOTOUL, M.; LEGUILLON, D.; MARTIN, É.; BERMEJO, R. Modelling of edge crack formation and propagation in ceramic laminates using the stress–energy coupled criterion. Engineering Fracture Mechanics, 2016, roč. 167, č. 2016, s. 45-55. ISSN: 0013-7944.

CHANG, Y.; BERMEJO, R.; ŠEVEČEK, O.; MESSING, G. Design of alumina-zirconia composites with spatially tailored strength and toughness. Journal of the European Ceramic Society, 2015, roč. 2015, č. 35, s. 631-640. ISSN: 0955-2219.

ŠEVEČEK, O.; BERMEJO, R.; KOTOUL, M. Prediction of the crack bifurcation in layered ceramics with high residual stresses. Engineering Fracture Mechanics, 2013, roč. 2013, č. 108, s. 120-138. ISSN: 0013- 7944.

Contact person
prof. RNDr. Michal Kotoul, DrSc.