Micromechanics of Piezocomposites
Abstract
Over the past two decades, materials engineers have developed piezoelectric-polymer composite materials that enable effective electromechanical properties to be tailored for a specific application. These materials are made by combining conventional piezoelectric ceramics with piezoelectrically passive polymers in a variety of geometrical configurations. As with any composite material, the properties and behavior of piezocomposites are highly dependent on the properties of the constituent materials and the local arrangement of the different phases. In particular, the ceramic-polymer interface plays an important role in determining the electromechanical coupling in the piezocomposite. In this dissertation, the electromechanical behavior of 1-3 piezocomposites is investigated from both theoretical and experimental stand points. Theoretical investigations centered on the development of a micromechanics model for predicting the local fields and effective behavior in piezocomposites with 1-3 connectivity. Since the presence of a thin interlayer or polymer coating around the ceramic rods can influence the local interaction between the piezoceramic and polymer matrix and change the overall performance of the composite, a finite composite cylinder model was developed to incorporate an interlayer with varying properties. Experimental studies focused on probing the surface displacements of 1-3 piezocomposites using a scanning heterodyne laser interferometer. Static surface displacements of 1-3 PZT rodepoxy samples with different interphase regions were measured and correlated with the effective low-frequency performance of the composite. Several types of interphase region were considered. Coatings with elastic moduli lower than that of the epoxy matrix were applied to the rods. The influence of a silane coupling agent was also investigated. Experimental displacement profiles were compared with micromechanical predictions using the finite composite cylinder model.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 28, 1995
- Accession Number
- ADA607648
Entities
People
- Li Li
Organizations
- University of Illinois Urbana–Champaign