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Title: CTH: A Code Family for Multidimensional Shock Physics Analysis.

Abstract

Abstract not provided.

Authors:
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1266960
Report Number(s):
SAND2007-0675C
524108
DOE Contract Number:
AC04-94AL85000
Resource Type:
Conference
Resource Relation:
Conference: Proposed for presentation at the WSSX Meeting held February 7-9, 2007 in Moscow, Russia.
Country of Publication:
United States
Language:
English

Citation Formats

Hertel, Eugene S.,. CTH: A Code Family for Multidimensional Shock Physics Analysis.. United States: N. p., 2007. Web.
Hertel, Eugene S.,. CTH: A Code Family for Multidimensional Shock Physics Analysis.. United States.
Hertel, Eugene S.,. Thu . "CTH: A Code Family for Multidimensional Shock Physics Analysis.". United States. doi:. https://www.osti.gov/servlets/purl/1266960.
@article{osti_1266960,
title = {CTH: A Code Family for Multidimensional Shock Physics Analysis.},
author = {Hertel, Eugene S.,},
abstractNote = {Abstract not provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Feb 01 00:00:00 EST 2007},
month = {Thu Feb 01 00:00:00 EST 2007}
}

Conference:
Other availability
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  • CTH is a family of codes developed at Sandia National Laboratories for modeling complex multi-dimensional, multi-material problems that are characterized by large deformations and/or strong shocks. A two-step, second-order accurate Eulerian solution algorithm is used to solve the mass, momentum, and energy conservation equations. CTH includes models for material strength, fracture, porous materials, and high explosive detonation and initiation. Viscoplastic or rate-dependent models of material strength have been added recently. The formulations of Johnson-Cook, Zerilli-Armstrong, and Steinberg-Guinan-Lund are standard options within CTH. These models rely on using an internal state variable to account for the history dependence of material response.more » The implementation of internal state variable models will be discussed and several sample calculations will be presented. Comparison with experimental data will be made among the various material strength models. The advancements made in modelling material response have significantly improved the ability of CTH to model complex large-deformation, plastic-flow dominated phenomena. Detonation of energetic material under shock loading conditions has been of great interest. A recently developed model of reactive burn for high explosives (HE) has been added to CTH. This model along with newly developed tabular equations-of-state for the HE reaction by-products has been compared to one- and two-dimensional explosive detonation experiments. These comparisons indicate excellent agreement of CTH predictions with experimental results. The new reactive burn model coupled with the advances in equation-of-state modeling make it possible to predict multi-dimensional burn phenomena without modifying the model parameters for different dimensionality. Examples of the features of CTH will be given. The emphasis in simulations shown will be in comparison with well characterized experiments covering key phenomena of shock physics.« less
  • CTH is a software system under development at Sandia National Laboratories Albuquerque to model multidimensional, multi-material, large deformation, strong shock wave physics. One-dimensional, two-dimensional, and three-dimensional Eulerian meshes are currently available. CTH uses tabular or analytic equations of state that model solid, liquid, vapor, plasma, and mixed-phase materials. CTH can model elastic-plastic behavior, high explosives, fracture, and motion of fragments smaller than a computational cell. CTH was carefully structured to vectorize and multitask on the CRAY X-MP. Three-dimensional databases reside on the CRAY solid state disk with only five planes in core at once. The input/output to the solid statemore » disk is overlapped with computations so there is no penalty for using the solid state disk. This allows very large problems to be run effectively. A sophisticated post-processor, CTHED, has been developed for interactive analysis using color graphics. This paper describes the architecture, database structure, models, and novel features of CTH. Special emphasis will be place on the features that are novel to CTH or are not direct generalizations of two-dimensional models. 8 refs., 1 fig.« less
  • CTH is a software system under development at Sandia National Laboratories Albuquerque to model multidimensional, multi-material, large deformation, strong shock wave physics. One-dimensional rectilinear, cylindrical, and spherical meshes; two-dimensional rectangular, and cylindrical meshes; and three-dimensional rectangular meshes are currently available. A two-step Eulerian solution scheme is used with these meshes. The first step is a Lagrangian step in which the cells distort to follow the material motion. The second step is a remesh step where the distorted cells are mapped back to the Eulerian mesh. CTH has several models that are useful for simulating strong shock, large deformation events. Bothmore » tabular and analytic equations of state are available. CTH can model elastic-plastic behavior, high explosive detonation, fracture, and motion of fragments smaller than a computational cell. The elastic-plastic model is elastic-perfectly plastic with thermal softening. A programmed burn model is available for modelling high explosive detonation. The Jones-Wilkins-Lee equation of state is available for modelling high explosive reaction products. Fracture can be initiated based on pressure or principle stress. A special model is available for moving fragments smaller than a computational cell with statistically the correct velocity. This model is very useful for analyzing fragmentation experiments and experiments with witness plates. This paper describes the models, and novel features of CTH. Special emphasis will be placed on the features that are novel to CTH or are not direct generalizations of two-dimensional models. Another paper by Trucano and McGlaun describes several hypervelocity impact calculations using CTH. (9 refs., 5 figs.)« less
  • Computer simulations of several hypervelocity impact events using the multi-dimensional, multi-material CTH shock wave physics code are presented and discussed. First, some two-dimensional CTH calculations are presented. These are then compared with calculations using another Eulerian shock wave physics code (CSQ) and with flash x-ray photographs of the impact events. Fully three-dimensional computations, including simulations of oblique impacts, will then be presented. Possible improvements in the physical and computational models used in the calculations will be mentioned. The influence of these calculations on CTH development will be discussed.
  • CTH is a code system under development at Sandia National Laboratories to model multidimensional, multi-material, large deformation, strong shock physics. One-dimensional, two-dimensional and three-dimensional Eulerian capabilities have been implemented first. Highly accurate analytic and tabular equations of state with solid, liquid, vapor, gas-liquid mixed phase and solid-liquid mixed phase capabilities can be used. The architecture of CTH was designed to accommodate other numerical approaches such as Lagrangian or ALE methods. CTH was carefully structured to run fast on a CRAY XMP. It is highly vectorized and multitasked. We briefly discuss the models used in CTH, techniques used to multitask themore » code and example calculations.« less