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1 03 - tensor calculus 03 - introduction to vectors and tensors holzapfel nonlinear solid mechanics [2000], chapter 1.6-1.9, pages 32-55 2 introduction me338 - syllabus 3 tensor calculus tensor the word tensor was introduced in 1846 by william rowan hamilton. it was used in its current meaning by woldemar voigt in 1899. tensor calculus was deve- loped around 1890 by gregorio ricci-curba- stro under the title absolute differential calculus. in the 20th century, the subject came to be known as tensor analysis, and achieved broader acceptance with the intro- duction of einsteins's theory of general relativity around 1915. tensors are used also in other fields such as continuum mechanics. tensor calculus 4 tensor calculus tensor analysis vector algebra notation, euklidian vector space, scalar product, vector product, scalar triple product notation, scalar products, dyadic product, invariants, trace, determinant, inverse, spectral decomposition, sym-skew decomposition, vol-dev decomposition, orthogonal tensor derivatives, gradient, divergence, laplace operator, integral transformations tensor algebra tensor calculus
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03 - introduction me338 - syllabus to vectors and tensorsbiomechanics.stanford.edu/me338_13/me338_s03.pdf · to vectors and tensors holzapfel nonlinear solid mechanics ... • tensor

Jul 03, 2018

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Page 1: 03 - introduction me338 - syllabus to vectors and tensorsbiomechanics.stanford.edu/me338_13/me338_s03.pdf · to vectors and tensors holzapfel nonlinear solid mechanics ... • tensor

1 03 - tensor calculus

03 - introduction to vectors and tensors

holzapfel �nonlinear solid mechanics� [2000], chapter 1.6-1.9, pages 32-55

2 introduction

me338 - syllabus

3 tensor calculus

tensor the word tensor was introduced in 1846 by william rowan hamilton. it was used in its current meaning by woldemar voigt in 1899. tensor calculus was deve-loped around 1890 by gregorio ricci-curba-stro under the title absolute differential calculus. in the 20th century, the subject came to be known as tensor analysis, and achieved broader acceptance with the intro-duction of einsteins's theory of general relativity around 1915. tensors are used also in other fields such as continuum mechanics.

tensor calculus

4 tensor calculus

• tensor analysis

• vector algebra notation, euklidian vector space, scalar product, vector product, scalar triple product

notation, scalar products, dyadic product, invariants, trace, determinant, inverse, spectral decomposition, sym-skew decomposition, vol-dev decomposition, orthogonal tensor

derivatives, gradient, divergence, laplace operator, integral transformations

• tensor algebra

tensor calculus

Page 2: 03 - introduction me338 - syllabus to vectors and tensorsbiomechanics.stanford.edu/me338_13/me338_s03.pdf · to vectors and tensors holzapfel nonlinear solid mechanics ... • tensor

5 tensor calculus

• euklidian norm enables definition of scalar (inner) product

• properties of scalar product

• positive definiteness • orthogonality

vector algebra - scalar product

6 tensor calculus

• vector product

• properties of vector product

vector algebra - vector product

7 tensor calculus

• scalar triple product

• properties of scalar triple product

area volume

• linear independency

vector algebra - scalar triple product

8 tensor calculus

• scalar (inner) product

• properties of scalar product

of second order tensor and vector

• zero and identity • positive definiteness

tensor algebra - scalar product

Page 3: 03 - introduction me338 - syllabus to vectors and tensorsbiomechanics.stanford.edu/me338_13/me338_s03.pdf · to vectors and tensors holzapfel nonlinear solid mechanics ... • tensor

9 tensor calculus

• scalar (inner) product

• properties of scalar product

of two second order tensors and

• zero and identity

tensor algebra - scalar product

·

10 tensor calculus

• scalar (inner) product

of fourth order tensors and second order tensor • zero and identity

• scalar (inner) product of two second order tensors

tensor algebra - scalar product

11 tensor calculus

• dyadic (outer) product

• properties of dyadic product (tensor notation) of two vectors introduces second order tensor

tensor algebra - dyadic product

12 tensor calculus

• (principal) invariants of second order tensor

• derivatives of invariants wrt second order tensor

tensor algebra - invariants

Page 4: 03 - introduction me338 - syllabus to vectors and tensorsbiomechanics.stanford.edu/me338_13/me338_s03.pdf · to vectors and tensors holzapfel nonlinear solid mechanics ... • tensor

13 tensor calculus

• trace of second order tensor

• properties of traces of second order tensors

tensor algebra - trace

14 tensor calculus

• determinant of second order tensor

• properties of determinants of second order tensors

tensor algebra - determinant

15 tensor calculus

• determinant defining vector product

• determinant defining scalar triple product

tensor algebra - determinant

16 tensor calculus

• inverse of second order tensor in particular

• properties of inverse

• adjoint and cofactor

tensor algebra - inverse

Page 5: 03 - introduction me338 - syllabus to vectors and tensorsbiomechanics.stanford.edu/me338_13/me338_s03.pdf · to vectors and tensors holzapfel nonlinear solid mechanics ... • tensor

17 tensor calculus

• eigenvalue problem of second order tensor

• spectral decomposition

• characteristic equation

• cayleigh hamilton theorem

• solution in terms of scalar triple product

tensor algebra - spectral decomposition

18 tensor calculus

• symmetric - skew-symmetric decomposition

• skew-symmetric tensor

• symmetric tensor

• symmetric and skew-symmetric tensor

tensor algebra - sym/skw decomposition

19 tensor calculus

• symmetric second order tensor

• square root, inverse, exponent and log

• processes three real eigenvalues and corresp.eigenvectors

tensor algebra - symmetric tensor

20 tensor calculus

• skew-symmetric second order tensor

• invariants of skew-symmetric tensor

• processes three independent entries defining axial vector such that

tensor algebra - skew-symmetric tensor

Page 6: 03 - introduction me338 - syllabus to vectors and tensorsbiomechanics.stanford.edu/me338_13/me338_s03.pdf · to vectors and tensors holzapfel nonlinear solid mechanics ... • tensor

21 tensor calculus

• volumetric - deviatoric decomposition

• deviatoric tensor

• volumetric tensor

• volumetric and deviatoric tensor

tensor algebra - vol/dev decomposition

22 tensor calculus

• orthogonal second order tensor

• proper orthogonal tensor has eigenvalue

• decomposition of second order tensor

such that and

interpretation: finite rotation around axis

with

tensor algebra - orthogonal tensor

23 tensor calculus

• frechet derivative (tensor notation)

• consider smooth differentiable scalar field with scalar argument vector argument tensor argument

scalar argument vector argument tensor argument

tensor analysis - frechet derivative

24 tensor calculus

• gateaux derivative,i.e.,frechet wrt direction (tensor notation)

• consider smooth differentiable scalar field with scalar argument vector argument tensor argument

scalar argument vector argument tensor argument

tensor analysis - gateaux derivative

Page 7: 03 - introduction me338 - syllabus to vectors and tensorsbiomechanics.stanford.edu/me338_13/me338_s03.pdf · to vectors and tensors holzapfel nonlinear solid mechanics ... • tensor

25 tensor calculus

• gradient of scalar- and vector field

• consider scalar- and vector field in domain

renders vector- and 2nd order tensor field

tensor analysis - gradient

26 tensor calculus

• divergence of vector- and 2nd order tensor field

• consider vector- and 2nd order tensor field in domain

renders scalar- and vector field

tensor analysis - divergence

27 tensor calculus

• laplace operator acting on scalar- and vector field

• consider scalar- and vector field in domain

renders scalar- and vector field

tensor analysis - laplace operator

28 tensor calculus

• useful transformation formulae (tensor notation)

• consider scalar,vector and 2nd order tensor field on

tensor analysis - transformations

Page 8: 03 - introduction me338 - syllabus to vectors and tensorsbiomechanics.stanford.edu/me338_13/me338_s03.pdf · to vectors and tensors holzapfel nonlinear solid mechanics ... • tensor

29 tensor calculus

• integral theorems (tensor notation)

• consider scalar,vector and 2nd order tensor field on

green gauss gauss

tensor analysis - integral theorems

30 tensor calculus

• integral theorems (tensor notation)

• consider scalar,vector and 2nd order tensor field on

green gauss gauss

tensor analysis - integral theorems

31 tensor calculus

• stress tensors as vectors in voigt notation

• strain tensors as vectors in voigt notation

• why are strain & stress different? check energy expression!

voigt / matrix vector notation

32 tensor calculus

• fourth order material operators as matrix in voigt notation

• why are strain & stress different? check these expressions!

voigt / matrix vector notation