Los Alamos Women in Science
Northern Chapter of the New Mexico Network for
Women in Science and Engineering
LUNCHTIME TALK SERIES

Wednesday, April 12, 2000
11:30 am - 1:30 pm, Otowi cafeteria side room C, LANL

TALK at 12:00:
Irene J. Beyerlein, MST-8, LANL
"Micromechanical Stress Redistribution Models and
Their Implications on Statistical Failure of Composites"

ABSTRACT

" In this talk, I will present results from various shear lag models for stress redistributions from multiple fiber breaks in large, unidirectional continuous fiber composites. These shear lag analyses have the ability to calculate stress states around random arrangements of several hundreds of fiber breaks in composites, wherein the matrix is elastic, plastic, or viscoelastic or the interface is frictionally sliding. The theoretical framework of these models is presented, followed by some results for a few selected crack configurations, which provide some insight into the failure process. I will also make connections between 2D and 3D elastic shear lag analyses for a discrete fiber composite and continuum analyses, such as linear elasticity and linear elastic fracture mechanics. Agreement is quantified for simple configurations of fiber breaks. The implications of these stress concentration results on statistical crack formation are discussed. Closed form expressions for key fiber stress concentrations are applied in developing probabilistic strength theories. The analytical probability models predictions are shown to be in good agreement with empirical distributions from representative Monte Carlo simulations of elastic composite fracture. "

Nonmembers Welcome!

Sideroom C is reserved from 11:30 to 1:30 for people who like to eat earlier or later, and informal discussion. You are welcome to come for just the talk at noon, and questions are encouraged!

For driving directions to Otowi Cafeteria (TA-3, building 261) at LANL, see: http://www.lanl.gov/tools/maps
(direct link to map showing the Otowi Building: http://nis-www.lanl.gov/cgi-bin/wthi?ta=3&bldg=261).

UPCOMING LAWIS EVENTS

Women's History Month (March) Events
brought to you by the LANL Women's Diversity Working Group
see http://www.lanl.gov/orgs/dvo/wdwg/March2000.html
Tuesday, April 11: Career's and Curiousity at Espanola Middle School
Volunteers are needed to present science demonstrations to 7th graders.
This AAUW-sponsored activity is very worthwhile and rewarding!
For more information on the April 11 C&C, see http://home.lanl.gov/lawis/LunchTalks/C_and_C_000411.html
For information on how to organize one at your school, see http://www.t12.lanl.gov/home/dcg/CC/C+C.html
Tuesday, May 9: Lunch-Time Talk
11:30-1:30 (talk at 12:00), Cochiti Room, Oppenheimer Study Center, LANL
Lisa Gutierrez, Director of Diversity Office, LANL
Title TBA. This talk is jointly sponsored by the American Association of University Women (AAUW).
(link to abstract)

PAST LAWIS EVENTS

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LAWIS Lunch-Time Talk Organizer: Huyen Dinh, dinh@lanl.gov, 665-0737
LAWIS home page: http://home.lanl.gov/lawis
NMNWSE home page: http://www.nmnwse.org

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