Title: Scale bridging damage model for quasi-brittle metals informed with crack evolution statistics

Abstract

Computationally efficient methods for bridging length scales, from highly resolved micro/meso-scale models that can explicitly model crack growth, to macro-scale continuum models that are more suitable for modeling large parts, have been of interest to researchers for decades. In this work, an improved brittle damage model is presented for the simulation of dynamic fracture in continuum scale quasi-brittle metal components. Crack evolution statistics, including the number, length, and orientation of individual cracks, are extracted from high-fidelity, finite discrete element method (FDEM) simulations and used to generate effective material moduli that reflect the material’s damaged state over time. This strategy allows for the retention of small-scale physical behaviors such as crack growth and coalescence in continuum scale hydrodynamic simulations. However, the high-fidelity simulations required to generate the crack statistics are computationally expensive. Thus, steps were taken to produce a flexible constitutive model to reduce the number of costly high-fidelity simulations needed to produce accurate results. A new stress based degradation criterion is introduced for the degradation of individual material zones. This allows for the development of a heterogeneous damage distribution within the bulk material. Then a flow stress model is added to the hydrodynamic simulation to account for plasticity in quasi-brittlemore » materials. As a result, the effective moduli model can be applied to a larger range of materials. The effective moduli constitutive model is used to simulate beryllium flyer plate experiments. The results from the continuum scale simulations using statistics from a single high-fidelity simulation are found to be in excellent agreement with numerical and experimental velocity interferometer data. The same set of crack statistics are used to extrapolate the results of a higher rate flyer plate case using the effective moduli model. In conclusion, the extension of this model to higher rate cases shows promise for further reducing the number of costly high-fidelity simulations needed to generate crack statistics.« less

Authors:

Larkin, Kevin ^[1]; Rougier, Esteban  ^[2];

• Search DOE PAGES for author "Rougier, Esteban"
• Search DOE PAGES for ORCID "0000-0002-4624-2844"

Chau, Viet Tuan  ^[2];

• Search DOE PAGES for author "Chau, Viet Tuan"
• Search DOE PAGES for ORCID "0000-0003-0314-6817"

Srinivasan, Gowri  ^[2];

• Search DOE PAGES for author "Srinivasan, Gowri"
• Search DOE PAGES for ORCID "0000-0001-5784-0295"

Abdelkefi, Abdessattar ^[3]; Hunter, Abigail  ^[2]

• Search DOE PAGES for author "Hunter, Abigail"
• Search DOE PAGES for ORCID "0000-0002-0443-4020"

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+ Show Author Affiliations

1. New Mexico State Univ., Las Cruces, NM (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
3. New Mexico State Univ., Las Cruces, NM (United States)

Publication Date:

Fri Feb 28 00:00:00 EST 2020

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE Laboratory Directed Research and Development (LDRD) Program

OSTI Identifier:

1603990

Alternate Identifier(s):

OSTI ID: 1776112

Report Number(s):

LA-UR-19-24826
Journal ID: ISSN 0022-5096

Grant/Contract Number:  

89233218CNA000001; 20170103DR

Resource Type:

Accepted Manuscript

Journal Name:

Journal of the Mechanics and Physics of Solids

Additional Journal Information:

Journal Volume: 138; Journal Issue: C; Journal ID: ISSN 0022-5096

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; brittle fracture; shock loading; effective elastic moduli; crack statistics; finite-discrete element method