On computing the evolution of temperature for materials under dynamic loading

Journal Article · Tue Jul 24 00:00:00 EDT 2018 · International Journal of Plasticity

DOI:https://doi.org/10.1016/j.ijplas.2018.07.014· OSTI ID:1463559

Luscher, Darby Jon ^[1]; Buechler, Miles Allen ^[1]; Walters, David J. ^[1]; Bolme, Cynthia Anne ^[1]; Ramos, Kyle James ^[1]

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

Modeling and simulation of the dynamic response of materials is important to many applications including the development of armor systems, understanding the safety of explosives, and assessing the crashworthiness of vehicles. Within such applications it is often critical to accurately compute the evolution of the temperature because it is a state variable that affects the kinetics of competing active processes within the material (e.g., dislocation motion, phase transformation, decomposition). Depending on the selection of an independent state variable, e.g. temperature or entropy, the approach for computing temperature is well understood based on the thermodynamic framework attributed to Coleman and Noll. However, different computational codes used for modeling the dynamic response of materials adopt different independent state variables. In this work, two thermodynamically consistent strategies for computing the temperature of a coupled thermodynamic state are compared and implemented into two different Lagrangian computational codes. The equivalence of these two approaches is established through the numerical solutions of several test problems. Finally, the implication of various approximations made to each of these approaches within the literature are assessed in the context of uniaxial stress conditions (split Hopkinson pressure bar experiments) and uniaxial strain conditions (plate impact experiments). Here, it is shown that the temperature rate or energy partition approaches are equivalent when implemented in their complete forms, but that several common simplifying assumptions, that are warranted in the case of uniaxial stress, lead to significant errors in the resulting Hugoniot state for plate impact.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1463559
• Alternate ID(s): OSTI ID: 1703208
• Report Number(s): LA-UR--18-21769
• Journal Information: International Journal of Plasticity, Journal Name: International Journal of Plasticity Vol. 111; ISSN 0749-6419
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
constitutive model
continuum hydrocode
dynamic loading
finite element
plastic heating
shock physics
thermodynamics