2,779 research outputs found
Phelan, Edward Joseph
Biography o Edwadrd Joseph PHELAN, British civil servant of Irish descent and fourth Director of
the International Labour Office 1941-1946 (acting) and first Director-General of the
International Labour Organization 1941-1948
A distributional approach to the geometry of dislocations at the mesoscale
We develop a theory to represent dislocated single crystals at the mesoscopic
scale by considering concentrated effects, governed by the distribution theory
combined with multiple-valued kinematic fields. Our approach gives a new
understanding of the continuum theory of defects as developed by Kroener (1980)
and other authors. Fundamental 2D identities relating the incompatibility
tensor to the Frank and Burgers vectors are proved under global strain
assumptions relying on the geometric measure theory, thereby giving rise to
rigorous homogenisation from mesoscopic to macroscopic scale.Comment: article soumi
Damage-driven fracture with low-order potentials: asymptotic behavior, existence and applications
We study the -convergence of damage to fracture energy functionals in
the presence of low-order nonlinear potentials that allows us to model physical
phenomena such as fluid-driven fracturing, plastic slip, and the satisfaction
of kinematical constraints such as crack non-interpenetration. Existence
results are also addressedComment: 41 pages, 4 Figure
A damage-based temperature-dependent model for ductile fracture with finite strains and configurational forces
A temperature dependent model for ductile fractur
Damage-based fracture with electro-magnetic coupling
Acoupled elastic and electro-magnetic analysis is proposed including finite displacements and damage-based fracture. Piezo-electric terms are considered and resulting partial differential equations include a non-classical wave equation due to the specific constitutive law. The resulting wave equation is constrained and, in contrast with the traditional solutions of the decoupled classical electromagnetic
wave equations, the constraint is directly included in the analysis. The absence of free current density allows the expression of the magnetic field rate as a function of the electric field and therefore, under specific circumstances, removal of the corresponding magnetic degrees-offreedom. A Lagrange multiplier field is introduced to exactly enforce the divergence constraint, forming a three-field variational formulation (required to include thewave constraint). No vector-potential is required or mentioned, eliminating the need for gauges. The classical boundary conditions of electromagnetism are specialized and a boundary condition involving the electric field is obtained. The spatial discretization makes use of mixed bubble-based (of the MINI type) finite elementswith displacement, electric field and Lagrange multiplier degrees-of-freedom. Three verification examples are presented with very good qualitative conclusions and mesh-independence
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