CTH: A Software Family for Multi-Dimensional Shock Physics Analysis

Abstract

CTH is a family of codes developed at Sandia N_onal Laboratories for modelling complex " multi-dimensional, multi-material problems that are characterized by large de/Ormationsand/or strong shocks. A two-s_p, second-order accurateEulerian solution algorithm is used to solve themass, momen-_...._'_ C_[ mm, and energy conservation equations. CTH includes models for material strength, fracture, porous t_ "-_ materials, and high explosive detonation and initiation. [/ft.,' !.,., or rate-dependent models of material strength have been added recently. The formulations _U0 of Johno_3n-Cook,Vise°pla_c Zerilli-Annstrong, and Steinberg-Guina_|-Lundare standard options within CTI-LThese _ _ models rely on the use of an internal state variable (typically the equivalent plastic strain) to account for the histoq dependence of material response. The implementation of internal state variable models will be O _ T [ 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 signiticanfly improved the ability of CrH to model complex large-deformation, plasticflow dominated phenomena. The detonation of energetic material under shock loading conditions has been an area of great interest. A recently developed model of reactive burn for high explosives 0-lE) 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 bum model coupled _cg ___ g _ _ _ _ with the adw,pces in equation-of-state modeling make it possible to predict multi-dimensional bum phe-_. _-_ _ _ 8 _: _ _, _" nomena without modifying the model parameters for different dimensionality. Most current bum models 2. _o _, _ _ _ _., ,, = ct __g"g'_ _ o _ 8 _.__ do not accurately predict both one-dimensional plate acceleration experiments and two-dimensional cylin-_-_"._ _ _. _ _. :" b_" = der expansion experiments simultaneously. Our implementation is significant because it represents the _ _ o _ _ _ _ _ "first time a multi-dimensional model has been used to successfully predict multi-dimensional detonation _ o .., o ,_ _ _ _ z effects without requiringa modification of the model parameters.

Cold spraying – A materials perspective

“…A pioneering example is given by Dykhuizen et al [49]. They considered an axisymmetric model of particle impact under adiabatic conditions, using CTH, an Eulerian-based FEM software package developed at Sandia National Laboratories [50].…”

“…A pioneering example is given by Dykhuizen et al [49]. They considered an axisymmetric model of particle impact under adiabatic conditions, using CTH, an Eulerian-based FEM software package developed at Sandia National Laboratories [50].Their simulations showed the development of shape and field variables, such as temperature, during impact of a copper particle on a steel substrate for different impact velocities. These simulations indicated formation of material jets at the outer rim of the contact zone, similar to that observed in explosive welding, at impact velocities higher than 400 m/s.…”

Assessing the role of mini-applications in predicting key performance characteristics of scientific and engineering applications

“…CTH is a multi-material, large deformation, strong shock wave, solid mechanics code developed at Sandia National Laboratories [20]. CTH has models for multi-phase, elastic viscoplastic, porous and explosive materials, using secondorder accurate numerical methods to reduce dispersion and dissipation and produce accurate, efficient results.…”

MiniGhost : a miniapp for exploring boundary exchange strategies using stencil computations in scientific parallel computing.

“…CTH is a multi-material, large deformation, strong shock wave, solid mechanics code developed at Sandia National Laboratories [16]. It includes models for multi-phase, elastic viscoplastic, porous and explosive materials, using second-order accurate numerical methods to reduce dispersion and dissipation and produce accurate, efficient results.…”