Comparison between nonconforming movement methods

In this work, we compare two nonconforming movement techniques: the mortar element method and the Lagrange multipliers. We present a unified formulation that can be easily used for electrical machines analysis. The anti-periodicity conditions as well as the use of high-order interface are discussed. The obtained linear systems are compared and results are shown for a permanent magnet machine

I. Introduction

The TECHNIQUES based on Lagrange multipliers are very efficient to perform the movement, especially for electromotive force and torque evaluations, which are determinant to coupled or dynamic problems. This paper shows the way to obtain the final systems for mortar element method (MEM) [1], [2] and Lagrange multipliers method (LM) [3]. The aim of this work is to demonstrate that is possible to obtain the final system for MEM and for LM using the same matrices to couple the subdomains. We compare the final systems and the computational cost of the methods. In fact, the two methods produce the same results, but the final systems are different, and care must be taken to solve them. It is also verified that we can use high-order interface and anti-periodicity conditions with either MEM or LM.