Mohammad Asadzadeh - An Introduction to the Finite Element Method (FEM) for Differential Equations

1. Chapter 8

1. Chapter 1
2. Chapter 2
3. Chapter 3
4. Chapter 5
5. Chapter 6
6. Chapter 7
7. Chapter 8
8. Chapter 9

M. Asadzadeh

This edition first published 2021.

2021 John Wiley & Sons, Inc.

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Library of Congress CataloginginPublication Data

Names: Asadzadeh, M., author.

Title: An introduction to the finite element method for differential

equations / M. Asadzadeh.

Description: Hoboken, NJ : Wiley, [2020] | Includes bibliographical

references and index.

Identifiers: LCCN 2020008313 (print) | LCCN 2020008314 (ebook) | ISBN

9781119671640 (cloth) | ISBN 9781119671671 (adobe pdf) | ISBN

9781119671664 (epub)

Subjects: LCSH: Finite element method. | Differential equations.

Classification: LCC TA347.F5 A83 2020 (print) | LCC TA347.F5 (ebook) |

DDC 515/.35--dc23

LC record available at https://lccn.loc.gov/2020008313

LC ebook record available at https://lccn.loc.gov/2020008314

Cover Design: Wiley

Cover Image: Courtesy of: Mohammad Asadzadeh and Larisa Beilina

This book is an introduction to finite element methods (FEMs) used in the numerical solution of differential equations based on the piecewise polynomial approximations of the solutions. The presented material is accessible for upper undergraduates and starting graduate students in natural science and engineering. We mention three books for further and deeper study of FEM for differential equations.

Brenner, S.C. and Scott, L.R. The Mathematical Theory of Finite Element Methods. Springer, ed 3, 2017.

Ern, A. and Guermond, J.L. Theory and Practice of Finite Elements. Springer, 2004.

Larsson, S. and Thome, V. Partial Differential Equations with Numerical Methods. Springer, 2003.

The material is presented in three main theme.

(I) Basic theory: , contains introduction (and in some extend derivation) of basic ordinary and partial differential equations, their classifications, wellposedness (as the proof of Reisz and LaxMilgram Theorems) and formulation of the corresponding initial and initialboundary value problems. The concept of fundamental solutions using Green's functions approaches are discussed and necessary mathematical tools and environment are introduced in some details.

(II) Onespace dimensional problems: concern the polynomial approximations, polynomial interpolation, quadrature rules (numerical integration), iterative numerical methods to solve linear system of equations and finite element procedure for the onespace dimensional boundary value problems (BVPs), initial value problems (IVPs), and initial boundary value problems (IBVPs).

(III) Problems in higher () dimensional cases. This part is the matter of and is devoted to the generalization/extension of the results of Part II to higher dimensions. The proofs in higher dimensions do not, in general, require any additional ideas. More specifically, we have introduced the higherdimensional interpolation procedure and study the stability and convergence aspects of certain finite element approximation for, higherdimensional, Poisson, heat, wave, and convectiondiffusion equations. The convergence analysis are given both in the a priori (exact solution dependent) and a posteriori (computed solution/residual dependent) settings.

Whole or selected parts of the book is suitable as course material and for particular purposes. As outlined in table below, I have used some minor parts of ) and can be of interest for beginning graduates in applied math and engineering disciplines.

To conclude, the theory combined with approximation techniques and computer projects can give a better understanding of this useful tool (FEM) to solve differential equations. Finally, there are some easily implementable Matlab codes presented at the end of the book that are useful for freshmen in finite elements to test and check the theory through implementations.

Suggestions for possible course syllabus (what I have had)

Chapters/Sections	1 Semester	78 wk	Credits
1.11.4, 2.5, 2.6, 3, 57	3h/wk	6h/wk	5
1.11.4, 2.5, 2.6, 3, 510	4h/wk	8h/wk	7
except 9.2, 9.3, 10.2.310.2.4, 10.5.410.5.6
Whole material (includes Chapter )	6h/wk	10/wk	10

An intensive course for graduates in applied math/engineering.

All above configurations are associated with home and computer assignments. Examples of some assignments are given in Appendix C.