Failure and volume fraction dependent mechanical properties of composite sensors and actuators

Abstract

Composite actuators and sensors manufactured by combining a ferroelectric ceramic such as lead zirconate titanate and a passive phase such as a polymer are used in a variety of applications including SONAR, vibration damping, change of structural shape (morphing), and structural health monitoring. The composite route provides specific advantages, including tailored piezoelectric response, high strain, a degree of flexibility, and increased damage tolerance compared with conventional dense monolithic ceramic materials. For piezoelectric fibre composites, where fine-scale brittle ceramic fibres of 40 -800 mm diameter are introduced into a ductile polymer matrix, the composite strength and failure mechanism ultimately depend on the mechanical properties of each phase and their volume fraction. This article examines the mechanical properties of piezoelectric fibres and the matrix phase and discusses the possible influence of fibre volume fraction on mechanical properties and failure mechanism of the composite. The data are of particular use in determining the failure stress, failure strain, and failure mechanism of composite actuators and sensors subjected to high levels of stress, for example, in applications where such devices are embedded into host structures.

A new measurement method of piezoelectric properties of single ceramic fibres

“…The frequency is typically in the region from 2 to 3 mHz. Additionally, the limited displacement sensitivity of the DMA allows only the characterization of the high voltage behavior (butterfly 15 In the present work we describe a novel method for determination of the low and high voltage properties of single ceramic fibres at higher frequencies up to 100 Hz.…”

Static and Dynamic Analysis of Bistable Piezoelectric-Composite Plates for Energy Harvesting

“…If the alternating force applied to the harvester continues to increase it will eventually result in straining of the piezoelectric material beyond the previously predicted states. The maximum strain constraint in the piezoelectric material, previously found to be inactive, is therefore likely to be an important consideration for optimization studies based on the dynamics of the system; especially since the failure strain of the piezoelectric material is much smaller that the carbon-fiber reinforced laminate 18 . (a-b) 4N, (c-d) 6.8N, and (e-f) 8N.…”

“…Equation (18) can then be solved using Matlab's built in ODE solver ODE15S, using either one of the two static shapes as an initial start point.…”

Optimal Design of Elastomer Composites for Morphing Skins

“…8, represent the volume fraction of fibers. The upper and lower limits of the volume fraction of fibers in a laminate depends on the fiber packing and failure modes [10,15]. In this study, the design variables are allowed to vary between 20 to 60% volume fraction of fibers with a 5% increment.…”