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Page 1: Introduction to the Finite Element Method (FEM) I

This project has been funded with support from the European Commission.

This publication [communication] reflects the views only of the author, and the Commission cannot be held responsible for any use which

may be made of the information contained therein.

Introduction to the Finite Element Method (FEM) – I

Miroslav Halilovič, Bojan Starman, Janez Urevc, Nikolaj Mole

Faculty of Mechanical Engineering, University of Ljubljana 06/2021

Page 2: Introduction to the Finite Element Method (FEM) I

What is FEM?

2

[1] https://manilsuri.umbc.edu/what-are-finite-elements/[2] https://www.simscale.com/blog/2016/10/what-is-finite-element-method/

[2]

[1]

Page 3: Introduction to the Finite Element Method (FEM) I

What is FEM?

Finite Element Method:

- is a procedure for obtaining numerical approximation to the solution of a boundary value problem.

3

Page 4: Introduction to the Finite Element Method (FEM) I

What is FEM?

4

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

Page 5: Introduction to the Finite Element Method (FEM) I

What is FEM?

5

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

𝜎0𝜎0 π‘₯

𝑦

Page 6: Introduction to the Finite Element Method (FEM) I

What is FEM?

6

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

𝜎0𝜎0 π‘₯

𝑦

𝜎π‘₯π‘₯𝜎π‘₯π‘₯

Page 7: Introduction to the Finite Element Method (FEM) I

What is FEM?

7

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

𝜎0𝜎0

𝜎0

3𝜎0

π‘₯

𝑦

𝜎π‘₯π‘₯𝜎π‘₯π‘₯

Page 8: Introduction to the Finite Element Method (FEM) I

What is FEM?

8

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

πœŽπ‘–π‘— = πœŽπ‘–π‘—(u)

… searching for u(x,y)

𝜎0𝜎0

𝜎0

3𝜎0

π‘₯

𝑦

𝜎π‘₯π‘₯𝜎π‘₯π‘₯

Page 9: Introduction to the Finite Element Method (FEM) I

What is FEM?

9

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

πœŽπ‘–π‘— = πœŽπ‘–π‘—(u)

… searching for u(x,y)

πœŽπ‘–π‘— ∝ 𝛻u

𝜎0𝜎0

𝜎0

3𝜎0

π‘₯

𝑦

𝜎π‘₯π‘₯𝜎π‘₯π‘₯𝑐0 + 𝑐1π‘₯ + 𝑐2𝑦 𝑐0 + 𝑐1π‘₯ + 𝑐2𝑦 + 𝑐3 π‘₯ 𝑦

Page 10: Introduction to the Finite Element Method (FEM) I

What is FEM?

10

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

πœŽπ‘–π‘— = πœŽπ‘–π‘—(u)

… searching for u(x,y)

πœŽπ‘–π‘— ∝ 𝛻u

𝜎0 𝜎0

𝑐0 + 𝑐1π‘₯ + 𝑐2𝑦 + 𝑐3 π‘₯ 𝑦𝑐0 + 𝑐1π‘₯ + 𝑐2𝑦

Page 11: Introduction to the Finite Element Method (FEM) I

What is FEM?

11

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

πœŽπ‘–π‘— = πœŽπ‘–π‘—(u)

… searching for u(x,y)

𝐾 . 𝑒 = {𝐹}… written in terms of 𝑒

πœŽπ‘–π‘— ∝ 𝛻uk k k

k

𝜎0 𝜎0

Page 12: Introduction to the Finite Element Method (FEM) I

What is FEM?

12

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

πœŽπ‘–π‘— = πœŽπ‘–π‘—(u)

… searching for u(x,y)

𝐾 . 𝑒 = {𝐹}… written in terms of 𝑒

πΎπ‘”π‘™π‘œπ‘ . π‘’π‘”π‘™π‘œπ‘ = {πΉπ‘”π‘™π‘œπ‘}… solving for π‘’π‘”π‘™π‘œπ‘

πœŽπ‘–π‘— ∝ 𝛻uk k k

k

𝜎0 𝜎0

Page 13: Introduction to the Finite Element Method (FEM) I

What is FEM?

13

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

πœŽπ‘–π‘— = πœŽπ‘–π‘—(u)

… searching for u(x,y)

𝐾 . 𝑒 = {𝐹}

πΎπ‘”π‘™π‘œπ‘ . π‘’π‘”π‘™π‘œπ‘ = {πΉπ‘”π‘™π‘œπ‘}

… written in terms of 𝑒

… solving for π‘’π‘”π‘™π‘œπ‘

πœŽπ‘–π‘— ∝ 𝛻u

π‘’π‘”π‘™π‘œπ‘ β†’ πœ–π‘–π‘— β†’ πœŽπ‘–π‘—

k k k

k

k

k

𝜎0 𝜎0

Page 14: Introduction to the Finite Element Method (FEM) I

What is FEM?

14

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

πœŽπ‘–π‘— = πœŽπ‘–π‘—(u)

… searching for u(x,y)

𝐾 . 𝑒 = {𝐹}

πΎπ‘”π‘™π‘œπ‘ . π‘’π‘”π‘™π‘œπ‘ = {πΉπ‘”π‘™π‘œπ‘}

… written in terms of 𝑒

… solving for π‘’π‘”π‘™π‘œπ‘

πœŽπ‘–π‘— ∝ 𝛻uk k k

k

π‘’π‘”π‘™π‘œπ‘ β†’ πœ–π‘–π‘— β†’ πœŽπ‘–π‘—k k

𝜎0 𝜎0

𝜎0

3𝜎0

𝜎π‘₯π‘₯

Page 15: Introduction to the Finite Element Method (FEM) I

What is FEM?

15

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

πœŽπ‘–π‘— = πœŽπ‘–π‘—(u)

… searching for u(x,y)

𝐾 . 𝑒 = {𝐹}

πΎπ‘”π‘™π‘œπ‘ . π‘’π‘”π‘™π‘œπ‘ = {πΉπ‘”π‘™π‘œπ‘}

… written in terms of 𝑒

… solving for π‘’π‘”π‘™π‘œπ‘

πœŽπ‘–π‘— ∝ 𝛻uk k k

k

π‘’π‘”π‘™π‘œπ‘ β†’ πœ–π‘–π‘— β†’ πœŽπ‘–π‘—k k

𝜎0 𝜎0

𝜎0

3𝜎0

𝜎π‘₯π‘₯

Page 16: Introduction to the Finite Element Method (FEM) I

What is FEM?

16

Governing

Diff. Eq.

𝛀 …+ πšͺ … =0

πœŽπ‘–π‘— = πœŽπ‘–π‘—(u)

… searching for u(x,y)

𝐾 . 𝑒 = {𝐹}

πΎπ‘”π‘™π‘œπ‘ . π‘’π‘”π‘™π‘œπ‘ = {πΉπ‘”π‘™π‘œπ‘}

… written in terms of 𝑒

… solving for π‘’π‘”π‘™π‘œπ‘

πœŽπ‘–π‘— ∝ 𝛻uk k k

k

π‘’π‘”π‘™π‘œπ‘ β†’ πœ–π‘–π‘— β†’ πœŽπ‘–π‘—k k

𝜎0 𝜎0

𝜎0

3𝜎0

𝜎π‘₯π‘₯

Page 17: Introduction to the Finite Element Method (FEM) I

GIGO

17

[1] https://www.r-bloggers.com/2019/08/new-course-learn-advanced-data-cleaning-in-r

[1]

Page 18: Introduction to the Finite Element Method (FEM) I

Common FEM applications

18

β€’ Mechanical/Aerospace/Civil/Automotive Engineering

β€’ Structural/Stress Analysis

- Static/Dynamic

- Linear/Nonlinear

β€’ Fluid Flow

β€’ Heat Transfer

β€’ Electromagnetic Fields

β€’ Soil Mechanics

β€’ Biomechanics

Page 19: Introduction to the Finite Element Method (FEM) I

Common FEM applications

19

β€’ Mechanical/Aerospace/Civil/Automotive Engineering

β€’ Structural/Stress Analysis

- Static/Dynamic

- Linear/Nonlinear

β€’ Fluid Flow

β€’ Heat Transfer

β€’ Electromagnetic Fields

β€’ Soil Mechanics

β€’ Biomechanics

Page 20: Introduction to the Finite Element Method (FEM) I

STATIC Stress analysis

20

πœŽπ‘–π‘—

π‘₯

𝜎π‘₯π‘₯

𝑧

π‘¦πœŽπ‘¦π‘¦

πœŽπ‘§π‘§πœŽπ‘₯𝑦

𝜎π‘₯𝑧

πœŽπ‘¦π‘§ 𝜎π‘₯π‘¦πœŽπ‘¦π‘§

𝜎π‘₯𝑧

Common FEM applications

πœŽπ‘’π‘ž

fixed

π‘‘π‘–π‘ π‘π‘™π‘Žπ‘π‘’π‘šπ‘’π‘›π‘‘π‘ π‘ π‘‘π‘Ÿπ‘’π‘ π‘ π‘’π‘ 

Page 21: Introduction to the Finite Element Method (FEM) I

Modal analysis

21

Common FEM applications

π‘›π‘Žπ‘‘π‘’π‘Ÿπ‘Žπ‘™ π‘“π‘Ÿπ‘’π‘žπ‘’π‘’π‘›π‘π‘–π‘’π‘ π‘šπ‘œπ‘‘π‘’ π‘ β„Žπ‘Žπ‘π‘’π‘ 

supported

supported

Nozzle loads

π‘’π‘šπ‘Žπ‘”π‘›π‘–π‘‘π‘’π‘‘π‘’

Page 22: Introduction to the Finite Element Method (FEM) I

22

Common FEM applications

Heat transfer

β„Žπ‘’π‘Žπ‘‘ 𝑓𝑙𝑒π‘₯

π‘‘π‘’π‘šπ‘π‘’π‘Ÿπ‘Žπ‘‘π‘’π‘Ÿπ‘’β„Žπ‘’π‘Žπ‘‘ 𝑓𝑙𝑒π‘₯

Page 23: Introduction to the Finite Element Method (FEM) I

23

Common FEM applications

Transient thermo-hydraulic simulation (Fluid dynamics)

π‘Šπ΄π‘‡πΈπ‘… π‘‘π‘œπ‘šπ‘Žπ‘–π‘›

π‘‡π‘’π‘šπ‘π‘’π‘Ÿπ‘Žπ‘‘π‘’π‘Ÿπ‘’

π‘£π‘’π‘™π‘œπ‘π‘–π‘‘π‘¦

π‘Šπ΄π‘‡πΈπ‘…

𝐴𝐼𝑅

Page 24: Introduction to the Finite Element Method (FEM) I

24

Common FEM applications

Coupled problems: Fluid-Structure Interaction (FSI)

inflow

t t

p

outflow

v

π‘Ÿπ‘’π‘ π‘π‘œπ‘›π‘ π‘’ π‘œπ‘“ π‘ π‘œπ‘™π‘–π‘‘π‘Ÿπ‘’π‘ π‘π‘œπ‘›π‘ π‘’ π‘œπ‘“ 𝑓𝑙𝑒𝑖𝑑

Page 25: Introduction to the Finite Element Method (FEM) I

25

simulation

Page 26: Introduction to the Finite Element Method (FEM) I

FEM simulation steps

26

1. Geometryβ€’ geometrical simplificationsβ€’ reduction of dimensions

2. Physical propertiesβ€’ material properties

β€’ structural properties

3. Geometrical discretizationβ€’ element type

β€’ meshing

4. Type of analysis

5. Loading and Boundary/Initial conditions

6. Presentation and analysis of results

Page 27: Introduction to the Finite Element Method (FEM) I

FEM simulation steps

27

1. Geometryβ€’ geometrical simplificationsβ€’ reduction of dimensions

2. Physical propertiesβ€’ material properties

β€’ structural properties

3. Geometrical discretizationβ€’ element type

β€’ meshing

4. Type of analysis

5. Loading and Boundary/Initial conditions

6. Presentation and analysis of results

Page 28: Introduction to the Finite Element Method (FEM) I

FEM simulation steps

28

[1] Carlos A. Felippa, 2004, Introduction to Finite Element Methods. Available at: https://vulcanhammernet.files.wordpress.com/2017/01/ifem.pdf (06/2021)

[1]

1. Geometryβ€’ geometrical simplificationsβ€’ reduction of dimensions

2. Physical propertiesβ€’ material properties

β€’ structural properties

3. Geometrical discretizationβ€’ element type

β€’ meshing

4. Type of analysis

5. Loading and Boundary/Initial conditions

6. Presentation and analysis of results

Page 29: Introduction to the Finite Element Method (FEM) I

FEM simulation steps

29

1. Geometryβ€’ geometrical simplificationsβ€’ reduction of dimensions

2. Physical propertiesβ€’ material properties

β€’ structural properties

3. Geometrical discretizationβ€’ element type

β€’ meshing

4. Type of analysis

5. Loading and Boundary/Initial conditions

6. Presentation and analysis of results

Page 30: Introduction to the Finite Element Method (FEM) I

FEM simulation steps

30

1. Geometryβ€’ geometrical simplificationsβ€’ reduction of dimensions

2. Physical propertiesβ€’ material properties

β€’ structural properties

3. Geometrical discretizationβ€’ element type

β€’ meshing

4. Type of analysis

5. Loading and Boundary/Initial conditions

6. Presentation and analysis of results

y

z

y

z

y

z

y

z

y

z

n

Page 31: Introduction to the Finite Element Method (FEM) I

FEM simulation steps

31

1. Geometryβ€’ geometrical simplificationsβ€’ reduction of dimensions

2. Physical propertiesβ€’ material properties

β€’ structural properties

3. Geometrical discretizationβ€’ element type

β€’ meshing

4. Type of analysis

5. Loading and Boundary/Initial conditions

6. Presentation and analysis of results

Page 32: Introduction to the Finite Element Method (FEM) I

FEM simulation steps

32

1. Geometryβ€’ geometrical simplificationsβ€’ reduction of dimensions

2. Physical propertiesβ€’ material properties

β€’ structural properties

3. Geometrical discretizationβ€’ element type

β€’ meshing

4. Type of analysis

5. Loading and Boundary/Initial conditions

6. Presentation and analysis of results

Page 33: Introduction to the Finite Element Method (FEM) I

FEM simulation steps

33

1. Geometryβ€’ geometrical simplificationsβ€’ reduction of dimensions

2. Physical propertiesβ€’ material properties

β€’ structural properties

3. Geometrical discretizationβ€’ element type

β€’ meshing

4. Type of analysis

5. Loading and Boundary/Initial conditions

6. Presentation and analysis of results

Page 34: Introduction to the Finite Element Method (FEM) I

FEM simulation steps

34

β€’ Static

β€’ Dynamic

β€’ Implicit

β€’ Explicit

β€’ Visco

β€’ Heat transferβ€’ Steady state

β€’ Transient

β€’ Coupled temperature-displacement

β€’ Buckling

β€’ Electromagnetism

β€’ Fluid Flow

- Linear

- Nonlinear

1. Geometryβ€’ geometrical simplificationsβ€’ reduction of dimensions

2. Physical propertiesβ€’ material properties

β€’ structural properties

3. Geometrical discretizationβ€’ element type

β€’ meshing

4. Type of analysis

5. Loading and Boundary/Initial conditions

6. Presentation and analysis of results

Page 35: Introduction to the Finite Element Method (FEM) I

FEM simulation steps

35

[1] Emri, I., Voloshin, A., 2016, Statics – Learning from Engineering Examples, Springer Science, doi: 10.1007/978-1-4939-2101-0

[1]

1. Geometryβ€’ geometrical simplificationsβ€’ reduction of dimensions

2. Physical propertiesβ€’ material properties

β€’ structural properties

3. Geometrical discretizationβ€’ element type

β€’ meshing

4. Type of analysis

5. Loading and Boundary/Initial conditions

6. Presentation and analysis of results

Page 36: Introduction to the Finite Element Method (FEM) I

FEM simulation steps

36

πœŽπ‘’π‘ž1. Geometry

β€’ geometrical simplificationsβ€’ reduction of dimensions

2. Physical propertiesβ€’ material properties

β€’ structural properties

3. Geometrical discretizationβ€’ element type

β€’ meshing

4. Type of analysis

5. Loading and Boundary/Initial conditions

6. Presentation and analysis of results

Page 37: Introduction to the Finite Element Method (FEM) I

Defining a simulation

37

β€’ Geometry

β€’ Sets

β€’ Material behaviour

β€’ Type of analysis

β€’ Solver type

β€’ Loading, Boundary/Initial conditions

β€’ Output

Page 38: Introduction to the Finite Element Method (FEM) I

Defining a simulation

38

β€’ Geometry

β€’ Sets

β€’ Material behaviour

β€’ Type of analysis

β€’ Solver type

β€’ Loading, Boundary/Initial conditions

β€’ Output

m n

o p

k

Page 39: Introduction to the Finite Element Method (FEM) I

Defining a simulation

39

β€’ Geometry

β€’ Sets

β€’ Material behaviour

β€’ Type of analysis

β€’ Solver type

β€’ Loading, Boundary/Initial conditions

β€’ Output

m n

o p

k

Page 40: Introduction to the Finite Element Method (FEM) I

Defining a simulation

40

β€’ Geometry

β€’ Sets

β€’ Material behaviour

β€’ Type of analysis

β€’ Solver type

β€’ Loading, Boundary/Initial conditions

β€’ Output

Page 41: Introduction to the Finite Element Method (FEM) I

Defining a simulation

41

β€’ Geometry

β€’ Sets

β€’ Material behaviour

β€’ Type of analysis

β€’ Solver type

β€’ Loading, Boundary/Initial conditions

β€’ Output

Static, Dynamic (Implicit, Explicit),Visco, Thermal, Coupled thermal-displacement,Linear/Nonlinear…

Equation solverSolution TechniquesIncrementationConvergence tolerances…

Page 42: Introduction to the Finite Element Method (FEM) I

Defining a simulation

42

β€’ Geometry

β€’ Sets

β€’ Material behaviour

β€’ Type of analysis

β€’ Solver type

β€’ Loading, Boundary/Initial conditions

β€’ Output

Page 43: Introduction to the Finite Element Method (FEM) I

Defining a simulation

43

β€’ Geometry

β€’ Sets

β€’ Material behaviour

β€’ Type of analysis

β€’ Solver type

β€’ Loading, Boundary/Initial conditions

β€’ Output

Page 44: Introduction to the Finite Element Method (FEM) I

Thank you for your attention!

http://sctrain.eu/

This project has been funded with support from the European Commission.

This publication [communication] reflects the views only of the author, and the Commission cannot be held responsible for any use which

may be made of the information contained therein.


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