Maxwell Stresses and Dielectric Materials (PDF)

Electrostatic stresses are a fascinating field where materials science, continuum mechanics and electrical engineering all come together. This is one of the reasons why the study of these so-called Maxwell stresses is so interesting.This treatment of electrostatic Maxwell stresses is restricted to the macroscopic description of the phenomenon, but an attempt is made to provide readers with methods and results which will allow them to deal with cases of low material symmetry, as well as with the effect of viscoelasticity upon the material response. Non-standard orientation of the material sample is studied in detail, because it is commonly encountered in laboratory practice, or is intentionally chosen so as to optimize a given device. A key advantage of the analysis presented in this book is seen in the fact that it permits the materials scientist who is planning experiments, or the technician who is designing novel electromechanical actuators, to predict the electrostatic stresses in terms of material constants. This also holds for the strains caused by electrostatic Maxwell stresses, and provides a valuable means for the analysis and optimization of electromechanical devices. The tools required to obtain these results are explained in detail. Where possible, a step-by-step derivation of the results is provided, so that the methods can be tailored to applications that are not treated in the book.In a nutshell, the contents are organized as follows: Chapters 2 to 6 deal with aspects of energy, momentum, symmetry and time. In chapter 7, some of the many applications of electrostatic Maxwell stresses are addressed in detail. Chapter 8 discusses the analogy with magnetostatic Maxwell stresses, and provides a more general derivation of the relationship between the force density and the corresponding stress tensor; thus reinforcing the chapter on momentum.Kloos, a physicist working in industry, takes a close look at specific electronic stresses while considering materials science, continuum mechanics and electrical engineering points of view. Although he limits coverage of the treatment of electrostatic Maxwell stresses to a macroscopic description, he also provides sufficient information so readers can deal with cases of low material symmetry as well as with the influence of viscoelasticity on the material response. He begins by describing Taylor expansion and interaction diagrams, electrostatic Maxwell stresses and quadratic electrostriction, then turns to derivation of the stress tensor from the force law, Maxwell stress tensors, Maxwell stress tensors at the boundary of a dielectric medium with another dielectric medium or with air, applications, including a viscoelastic case study in application to polymers, closing with an analogous phenomenon, magnetostatic Maxwell stresses.