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ME458 - BME487 NONLINEAR FINITE ELEMENT ANALYSIS |
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references: Cook4th:= R.D.Cook, D.S. Malkus, M.E. Plesha, R.J. Witt, Concepts and Applications of Finite Element Analysis, 4th ed., Wiley, 2001. Cook3rd:= R.D.Cook, D.S. Malkus, M.E. Plesha, Concepts and Applications of Finite Element Analysis, 3rd ed., Wiley, 1989. Bathe:= K-J Bathe, Finite Element Procedures, Prentice Hall 1996. Sahmes&Dym:=I.H. Shames and C.L. Dym, Energy and Finite Element Methods in Structural Mechanics, Taylor and Francis, 2003. Bonet&Wood:=J. Bonet and R.D. Wood, Nonlinear Continuum Mechanics for Finite Elemnt Analysis, Cambridge U. Press, 1997. Srinivasan &Perucchio:= R. Srinivasan and R. Perucchio, "Finite element analysis of anisotropic nonlinear incompressible elastic solids by a mixed model,” IJNME, 37, 3075-3092, 1994. |
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| 1/18/07 | 1 | 1-D linear elastic problem:
equilibrium
eq.s and boundary conditions, exact solution, finite difference
discretization, variational formulation, Rayleigh-Ritz
approximation. Ref: Cook4th: Ch. 4:4.1,4.2,4.3, 4.4 (focus on bar under axial load), 4.5, 4.6. |
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1/23/07
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1-D linear elastic problem: variational
formulation, Rayleigh-Ritz approximation with polynomial expansion,
principle of virtual works, R-R approximation based on domain
discretization. Ref: Cook4th: Ch. 4:4.1,4.2,4.3, 4.4 (focus on bar under axial load), 4.5, 4.6. |
| 1/25/07 |
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1-D linear
elastic problem: derivation
of
finite element (FE) formulation from Rayleigh-Ritz, equilibrium eq.s in
FE form, evaluation of [K]
for the linear 1-D element. Ref: Cook4th: Ch2:2.1, 2.2; Ch.3:3.2. |
| 1/30/07 | 4 | 1-D linear elastic problem: lagrangian shape functions (linear and
quadratic); isoparametric formulation of
bar element, assembly of global [K],
partitioning, boundary conditions, solution. Ref: Cook4th: Ch. 4:4.8. Ref: Cook3rd: Ch2:2.1-2.5. |
| 2/1/07 | 5 |
1-D linear elastic problem:
bar element in 2-D
Euclidean space: transformation from local to global co-ord.s,
transformation of the stiffness matrix. Ref: Cook3rd: Ch7: 7.1,7.2, 7.4, 7.5. Continuum mechanics: Cartesian tensors: vector transformations, definition of tensors, symmetry and skew symmetry, inner product, cross product. Ref: Shames&Dym: Appendix 1. Bathe: Ch2:2.3, 2.4. |
| 2/6/07 | 6 |
Continuum
mechanics: Cartesian tensors: field operators, Gauss theorem, Green's
formula, Kronecker delta, ex: tensorial nature of [K]. Continuum mechanics: Stress: force distributions, stress, Cauchy formula. Ref: Shames&Dym: Appendix 1. Ch1: 1.1-1.4. Bathe: Ch2:2.3, 2.4. |
| 2/7/07 | 7 |
Continuum
mechanics: Stress: equations of motion, stress symmetry, stress
is a second-order tensor, principal stresses and principal directions,
tensor invariants. Ref: Shames&Dym: Ch1: 1.4-1.6. |
| 2/8/07 | 8 |
Continuum
mechanics: Strain: Green and Almansi strains, infinitesimal
strains, engineering strains, physical interpretation of strain
components, variation of volume as a function of normal strains. Ref: Shames&Dym: Ch1: 1.7-1.8. |
| 2/12/07 | 9 | Continuum
mechanics: Strain: deformation gradient, rotation tensor,
transformation of strains,
compatibility equations. Ref: Shames&Dym: Ch1: 1.9-1.11. |
| 2/13/07 | 10 |
Continuum
mechanics: Constitutive laws: strain energy density
function, mechanical work during deformation, elastic behavior,
complementary strain energy. Ref: Shames&Dym: Ch1: 1.13. L |
| 2/14/07 | 11 | Continuum
mechanics: Constitutive laws: Hooke's law, Lame' constants for
homogeneous and isotropic linear elastic materials, Young's modulud and
Poisson's ratio. Ref: Shames&Dym: Ch1: 1.13. Linear finite elements: Derivation of the principle of virtual work. Ref: Cook4th: Ch3:3.1- 3.8. |
| 3/06/07 | 12 | Linear
finite elements: Isoparametric formulation: 1-D element, 2-D element,
Jacobian matrix, [B] matrix, numerical integration of [K]. Ref: Cook4th: Ch6:6.1- 6.3. Bathe: Ch5:5.1-5.2 . |
| 3/1/07 | 13 | Linear
finite elements: Isoparametric formulation: 1-D element, 2-D element,
Jacobian matrix, [B] matrix, numerical integration of [K]. Ref: Cook4th: Ch6:6.1- 6.3. Bathe: Ch5:5.1-5.2 . |
| 3/6/07 | 14 | Linear
finite elements: Isoparametric formulation: element distortions,
quarter-point element for
linear elastic fracture mechanics; stress calculation at Gauss points,
smoothed stress field built by extrapolation. Ref: Cook4th: Ch6:6.10 - 6.11. Bathe: Ch5:5.5.4, 5.5.5 |
| 3/20/07 | 15 | FE Nonlinear
Analysis: classification of nonlinear analysis, ex pr: elastic-plastic
bar, ex pr.: contact. Ref: Bathe: Ch6:6.1 |
| 3/21/07 | 16 | FE Nonlinear
Analysis: Ex pr: snap-through. Incremental solution algorithms,
Newton-Raphson iterations, modified Newton-Raphson iterations, load
increments vs. displacement increments. Ref: Bathe: Ch6:6.1 |
| 3/22/07 | 17 |
MIDTERM EXAM
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| 3/27/07 | 18 | Review and discussion of exam. |
| 3/29/07 | 19 | Continuum
mechanics: kinematics: Lagrangian formulation, deformation gradient,
mass density, computation of the deform. gradient for isoparametric
formulation, computation of the
defor. gradient for Lagrangian element. Ref: Bathe: Ch6:6.2.2 |
| 4/03/07 | 21 | Continuum
mechanics: kinematics: Cauchy-Green
deformation
tensor, stretch, angle between line elements, polar decomposition of
the defor. gradient. Ref: Bathe: Ch6:6.2.2 |
| 4/05/07 | cancelled |
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| 4/10/07 | 22 | Continuum
mechanics: kinematics:
right and left stretch, velocity gradient L, decomposition L=D+W Ref: Bathe: Ch6:6.2.2 |
| 4/12/07 | 23 | Continuum
mechanics: kinematics:
Green-Lagrange strain tensor, Hencky strain tensor, Rate of change of
G-L strais. Ref: Bathe: Ch6:6.2.2 |
| 4/17/07 | 24 | Continuum
mechanics: kinematics: relationship between
G-L strains and infinitesimal strains.
Second Piola-Kirchhoff stress tensor.Second
Piola-Kirchhoff stress tensor: properties. IIP-K stresses and
G-L strains are invariant under rigid body motions (objective measures). FE Nonlinear Formulation: transformation of internal virtual work, Total Lagrangian (TL) and Updated Lagrangian (UL) formulations. Ref: Bathe: Ch6:6.2.2-6.2.3 |
| 4/19/07 | 25 | FE Nonlinear
Formulation: incremental TL: eq. of motion, incremental decomposition
of stresses and strains, linearization, linearized incremental eq. of
motion; incremental UL: eq. of motion,
incremental decomposition of stresses and strains, linearization,
linearized incremental eq. of motion. Error due to linearization.
Newton-Raphson iterations for the T.L. formulation. Ref: Bathe: Ch6:6.2.3 |
| 4/24/07 | 26 | FE Nonlinear
Formulation: loading: deformation dependent; inertial forces.
Materially-nonlinear-only analysis. Displacement-based isoparametric
continuum formulation: linearization of V.W. w.r.t. FE variables.
Matrix equations: T.L. formulation, U.L. formulation,
Materially-nonlinear-only formulation Ref: Bathe: Ch6:6.3.1-6.3.2 |
| 4/26/07 | 27 | FE Nonlinear
Formulation: FE matrices; 2-D element (plane strain/stress): Jacobian
transformation, U.L. formulation, incremental strains, linear and
nonlinear B matrices. Ref: Bathe: Ch6:6.3.2-6.3.4 |
| 5/01/07 | 28 | FE Nonlinear
Formulation: solution process, elastic material models, generalized
Hooke's law, Almansi strain tensor and its properties.
Incompressibility: isochoric condition based on the Cauchy-Green strain
tensor, augmented hyperelastic strain energy density function. Ref: Bathe: Ch6:6.6 - 6.6.1 |
| 5/03/07 | 29 | ORAL EXAM |