in Prague, Czech Republic, on 14-18
September 2009
Theme
This course provides an overview of modeling approaches used in the
mechanics of inelastic materials and structures, with special attention
to the objective description of highly localized deformation modes such
as cracks or shear bands. In 2009, the course was attended by 21
participants from 11 European countries and the United States.
Main topics
Introduction: notation, fundamentals of
tensor
algebra, basic types of inelastic material behavior, principles of
incremental-iterative nonlinear analysis.
Elastoplasticity:
physical motivation, basic equations in one dimension, extension to
multiaxial stress, postulate of maximum plastic dissipation, associated
and nonassociated plastic flow, hardening and softening, tangent
stiffness.
Fracture
mechanics: stress concentration around defects,
asymptotic fields in the vicinity of a crack tip, local and global
criteria for crack propagation, fracture toughness and fracture energy,
nonlinear process zone, cohesive crack models.
Damage
mechanics: physical motivation, basic equations in one
dimension, isotropic damage models, smeared crack models, anisotropic
damage models based on principles of strain equivalence and of
energy equivalence, damage
deactivation due to crack closure, combination of damage and plasticity.
Strain
localization: physical aspects, structural size effect,
incipient weak discontinuity,
localization analysis based on acoustic tensor, loss of ellipticity and
its mathematical and numerical consequences, classification of models
for localized inelastic behavior.
Regularized
continuum models: classification of enriched continuum
theories, nonlocal formulations of the integral type, strain-gradient
models, explicit and
implicit models with gradients of internal variables, localization
analysis, implementation aspects,
application examples.
Strong
discontinuity models: cohesive crack and cohesive zone
models, finite elements with
incorporated
discontinuities (embedded crack models, extended finite elements),
direction of crack propagation.