Session: 02-10: Design, Modeling, and Behavior of Functional and Shape Memory Materials and Composites

Paper Number: 111901

111901 - Design Approach to Particulate-Based Multifunctional Polymer Composite Materials 

Multifunctional polymer composites (MPCs) have been known and studied for decades. This smart structure consists of a polymer matrix with dispersed inclusions such as piezoelectric and ferroelectric particles, rods, or platelets. The properties of these composites are dependent on the properties of the inclusions, which can have their mechanical, electrical, magnetic, and thermal properties modified by stress, temperature, electric field, or magnetic field. An example of a multifunctional polymer composite is a piezoelectric, with the ability to convert mechanical energy into electrical energy and vice versa. This property has been widely studied and exploited in various applications, including energy harvesting, sensing, and actuation. However, optimizing the design of these composites to enhance their piezoelectric properties is a challenge. Developing an effective polymer matrix composite with piezoelectric inclusions requires getting the electric field into the inclusions, yet the high permittivity of the inclusions causes the electric field to concentrate in the matrix. At the same time, the stiffness of the inclusions is generally higher than that of the matrix, leading to a stress concentration in the inclusion. The design objective of ferroelectric composites is to maximize the electric field intensity inside the ferroelectric phase so that it undergoes a deformation induced by the electric field, and to get this strain back into the polymer phase so that there is a corresponding macroscale deformation.

This work provides a study of the electro-elastic behavior of particulate-based multifunctional polymer composites under mechanical and electrical loading. A combination of closed form and computational approaches are presented to calculate the interactions between the inclusions and the matrix. The parameters studies include inclusion geometry, inclusion-inclusion interactions, effects of finite matrix conductivity, and effects of the addition of conducting particles.  Laplace's equation governs the elastostatics (elasticity), the electrostatic insulator, and the electrostatic finite conductivity problems. Closed form solutions are available for specific inclusion geometries in both 2-D and 3-D cases. The case of a ferroelectric inclusion with remanent polarization is also addressed. These closed form solutions are used to validate the computational models. Computational models are then used to study electrical and mechanical interactions between inclusions. A multi-inclusion model is built to predict the effective electroelastic properties of dielectric composites.

Presenting Author: Robin Collet UC Riverside

Presenting Author Biography: Robin Collet is a PhD student at the Marlan and Rosemary Bourns College of Engineering at the University of California, Riverside. After completing a two-year university degree from the Institute of Technology of Montluçon, France, he obtained a master degree in Mechanical Engineering with design and simulation specialization from the National Engineering School of Saint-Etienne (ENISE) - École Centrale de Lyon, France. His current research interests focus on mechanics of materials, smart materials, ferroelectricity and active structures.