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in creator/contributor: "Addessio, F.L."

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Improved coupling of the conduction and flow equations in TRAC. [PWR]

Recent nuclear-reactor-systems modeling efforts have been directed toward the development of computer codes capable of simulating transients in short computational times. For this reason, a stability enhancing two-stem method (SETS) has been applied to the two-phase flow equations in the Transient Reactor Analysis Code (TRAC) allowing the Courant limit to be violated. Unfortunately, the coupling between the wall conduction equation and the fluid-dynamics equations is performed semi-implicitly, … more

Date: January 1, 1981

Creator: Addessio, F.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The dynamic inelastic response of delaminated plates

A generalized theory for laminated plates with delaminations is used to consider the influence of inelastic deformations on the dynamic behavior of composite plates with delaminations. The laminate model is based on a generalized displacement formulation implemented at the layer level. The delamination behavior can be modeled using any general interfacial fracture law: however, for the current work a linear model is employed. The interfacial displacement jumps are expressed in an internally con… more

Date: December 1, 1996

Creator: Addessio, F.L. & Williams, T.O.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The dynamic response of inelastic, delaminated composite plates

The dynamic behavior of metal matrix composite (MMC) plates is considered. In particular, the influence of inelastic deformations and delamination at the interfaces of the lamina on the macroscopic and local response of Al{sub 2}O{sub 3}/Al plates are studied. The work is carried out using a recently developed plate theory which models both delamination and localized history-dependent effects such, as inelasticity. A linear debonding model for the interface is employed for the current work. The… more

Date: April 1, 1997

Creator: Williams, T.O. & Addessio, F.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A cell model for homogenization of fiber-reinforced composites: General theory and nonlinear elasticity effects

The theoretical basis of the homogenization technique developed by Aboudi is presented and assessed. Given the constitutive relations of the constituents, this technique provides an equivalent, homogeneous, constitutive model of unidirectional, continuous-fiber-reinforced composites. The expressions that comprise the first-order version of the technique are given special attention as this treatment has considerable practical value. Nonlinear elasticity effects are added to it. This extension in… more

Date: November 1, 1995

Creator: Aidun, J.B. & Addessio, F.L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

High strain-rate model for fiber-reinforced composites

Numerical simulations of dynamic uniaxial strain loading of fiber-reinforced composites are presented that illustrate the wide range of deformation mechanisms that can be captured using a micromechanics-based homogenization technique as the material model in existing continuum mechanics computer programs. Enhancements to the material model incorporate high strain-rate plastic response, elastic nonlinearity, and rate-dependent strength degradation due to material damage, fiber debonding, and del… more

Date: July 1, 1995

Creator: Aidun, J.B. & Addessio, F.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

CAVEAT-GT: A general topology version of the CAVEAT code

We describe a numerical technique for solving two-dimensional, compressible, multimaterial problems using a general topology mesh. Multimaterial problems are characterized by the presence of interfaces whose shapes may become arbitrarily complex in the course of dynamic evolution. Computational methods based on more conventional fixed-connectivity quadrilateral meshes do not have adequate flexibility to follow convoluted interface shapes and frequently fail due to excessive mesh distortion. The… more

Date: June 1, 1990

Creator: Cline, M. C.; Dukowicz, J. K. & Addessio, F. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

A thermodynamically consistent, damage-dependent, interface debonding model for composites

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The ability to design composite materials and analyze processing procedures relies on the availability of constitutive models that describe their dynamic response accurately. The strength, damage evolution, and failure of interfaces within composites often dominate their macroscopic performance but are not well characterized. The design of such comp… more

Date: December 31, 1998

Creator: Johnson, J.N.; Clements, B.E.; Addessio, F.L. & Williams, T.O.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

MESA: A 3-D computer code for armor/anti-armor applications

We describe a new 3-D computer code, named MESA, developed at the Los Alamos National Laboratory with DARPA/Army/Marine Corps support specifically for simulations of armor and anti-armor systems. MESA is a three-dimensional, cartesian, Eulerian code with hydrodynamics, high explosives, and material strength models. Among special features of MESA are its high-order advection algorithm, its material interface tracking scheme and the van Leer monotonic advection limiting. We will briefly illustrat… more

Date: January 1, 1989

Creator: Mandell, D. A.; Adams, T. F.; Holian, K. S.; Addessio, F. L.; Baumgardner, J. R. & Mosso, S. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department