Fundamental Equations

Abstract

The derivation of the fundamental equations of the couple-stress theory presented in this section is mainly based on paper [1] by W. T. Koiter with certain modifications. The indicial notation (Cartesian tensors) is used throughout the paner. The summation convention holds for repeated indices (except for the index n denoting the direction normal to the surface). The permutation symbol is denoted є_ijk hic and assumes the values of +1, −1, 0, depending on whether the permutation of indices is even, odd or some indices are repeated. Vectors, denoted in print by bold-face letters, are underlined in this text.