Dynamic brittle material response based on a continuum damage model
Abstract
Because of its potential utilization in energy exploration and defense applications, the phenomenon of brittle fracture in solids under dynamic loads has been an ongoing topic of interest. A continuum damage model was developed to simulate rock fragmentation induced by explosive blasts for in situ oil shale retorting. The model was based on the premise that the inelastic brittle response exhibited by rock under dynamic loads is due principally to the stressinduced subscale cracks. Locally, the growth and interaction of these subscale cracks relieve portions of the material volume and reduce its capability to carry load. Globally, this effect is reflected in the degradation of the material stiffness. In this manner, the dynamic fracture process was modeled as a continuous accrual of damage, where damage is considered to be the degree of reduction of the material stiffness. Reasonable correlations between calculated and measured data were obtained by this model. Although the model has achieved some degree of success, some deficiencies have been identified over the years. For example, the adequacy of representing the compressive response by perfect plasticity was questioned. Because of the damage formulation, strainsoftening and localization are natural byproducts of the model. Thus, a question on meshsize dependencymore »
 Authors:

 Sandia National Lab., Albuquerque, NM (United States)
 Publication Date:
 Research Org.:
 Sandia National Laboratory
 OSTI Identifier:
 175434
 Report Number(s):
 CONF950686
TRN: 95:0061110424
 DOE Contract Number:
 AC0494AL85000
 Resource Type:
 Conference
 Resource Relation:
 Conference: Joint applied mechanics and materials summer meeting, Los Angeles, CA (United States), 2830 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of AMD  MD `95: Summer conference; PB: 520 p.
 Country of Publication:
 United States
 Language:
 English
 Subject:
 04 OIL SHALES AND TAR SANDS; OIL SHALES; EXPLOSIVE FRACTURING; CORRELATIONS; DYNAMIC LOADS; PLASTICITY; RETORTING; STRAIN SOFTENING; YIELD STRENGTH; FRACTURE MECHANICS
Citation Formats
Chen, E P. Dynamic brittle material response based on a continuum damage model. United States: N. p., 1995.
Web.
Chen, E P. Dynamic brittle material response based on a continuum damage model. United States.
Chen, E P. Sun .
"Dynamic brittle material response based on a continuum damage model". United States.
@article{osti_175434,
title = {Dynamic brittle material response based on a continuum damage model},
author = {Chen, E P},
abstractNote = {Because of its potential utilization in energy exploration and defense applications, the phenomenon of brittle fracture in solids under dynamic loads has been an ongoing topic of interest. A continuum damage model was developed to simulate rock fragmentation induced by explosive blasts for in situ oil shale retorting. The model was based on the premise that the inelastic brittle response exhibited by rock under dynamic loads is due principally to the stressinduced subscale cracks. Locally, the growth and interaction of these subscale cracks relieve portions of the material volume and reduce its capability to carry load. Globally, this effect is reflected in the degradation of the material stiffness. In this manner, the dynamic fracture process was modeled as a continuous accrual of damage, where damage is considered to be the degree of reduction of the material stiffness. Reasonable correlations between calculated and measured data were obtained by this model. Although the model has achieved some degree of success, some deficiencies have been identified over the years. For example, the adequacy of representing the compressive response by perfect plasticity was questioned. Because of the damage formulation, strainsoftening and localization are natural byproducts of the model. Thus, a question on meshsize dependency has also been raised. This investigation is concerned with the improvement of the damage model in by including the DruckerPrager model to represent compressional response and nonlocal treatment to tensile damage. The inclusion of the DruckerPrager model allows pressuredependent yield strength representation. Although the ratedependent nature of the model may alleviate the meshsize dependence problem, a nonlocal formulation was also investigated to insure meshsize independency. This treatment is based on the nonlocal representation with local strain.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1995},
month = {12}
}