Electromechanical instabilities in periodic dielectric elastomer composites. (15th May 2020)

• Record Type: Journal Article
• Authors: Jandron, Michael; Henann, David L.
• Is Part Of: International journal of solids and structures. Volume 191/192(2020)
• Page Start: 220
• Page End: 242
• Publication Date: 2020-05-15
• Subjects: Dielectric elastomers -- Composite materials -- Electromechanical instability -- Finite-element method; Mechanics, Applied -- Periodicals; Structural analysis (Engineering) -- Periodicals; Elastic solids -- Periodicals; Mécanique appliquée -- Périodiques; Constructions, Théorie des -- Périodiques; Solides élastiques -- Périodiques; Elastic solids; Mechanics, Applied; Structural analysis (Engineering); Periodicals; 624.18
• DOI: 10.1016/j.ijsolstr.2019.12.008
• Languages: English
• ISSNs: 0020-7683

Abstract

Abstract: Several types of electromechanical instability emerge in periodic dielectric elastomer (DE) composites – either limiting the range of electromechanical actuation or providing an opportunity to harness instabilities for enhanced functionality. The electromechanical pull-in instability – extensively studied in monolithic DEs – is also encountered in periodic DE composites, and additional instability types – microscopic, macroscopic, and interfacial instabilities – arise in DE composites. For general DE composites subjected to arbitrary electromechanical loading, numerical simulation is required to detect all types of instability. In this paper, using a finite-element-based numerical simulation capability, we consider electromechanical instabilities in DE composites consisting of periodic lattices of aligned circular-cross-section fibers embedded in a matrix. We report on several types of electromechanical instabilities that are known to occur in this type of DE composite: (1) pull-in, (2) microscopic, (3) macroscopic, and (4) interfacial instabilities, while surveying a comprehensive parameter space. Namely, the roles of shear modulus contrast, electric permittivity contrast, fiber volume fraction, chain-locking behavior, mechanical prestress, prestretch, and confinement are considered. The result is an overarching view of the instability landscape in periodic, fiber-based DE composites. We conclude by showing that microscopic instabilities may be harnessed to invoke electric-field-triggered pattern transformations in certain cases.