Acta Mechanica

, Volume 175, Issue 1–4, pp 1–18 | Cite as

A consistent modified Zerilli-Armstrong flow stress model for BCC and FCC metals for elevated temperatures

  • F. H. Abed
  • G. Z. Voyiadjis


The Zerilli-Armstrong (Z-A) physical based relations that are used in polycrystalline metals at low and high strain rates and temperatures are investigated in this work. Despite the physical bases used in the derivation process, the Z-A model exhibits certain inconsistencies and predicts inaccurate results when applied to high temperatures-related problems. In the Z-A model, the thermal stress component vanishes only when T→∞. This contradicts the thermal activation mechanism that imposes an athermal behavior for the flow stress at certain finite critical temperatures. These inconsistencies, in fact, are attributed to certain assumptions used in the Z-A model formulation that causes the model parameters to be inaccurately related to the microstructural physical quantities. New relations are, therefore, suggested and proposed in this work using the same physical bases after overcoming any inappropriate assumptions. The proposed modified relations along with the Z-A relations are evaluated using the experimental results for different bcc and fcc metals. Comparisons are also made with the available experimental results over a wide range of temperatures and strain rates. The proposed model simulations, in general, show better correlation than the Z-A model particularly at temperatures values above 300K. Numerical identification for the physical quantities used in the definition of the proposed model parameters is also presented.


Thermal Stress Critical Temperature Flow Stress Physical Quantity High Strain Rate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Wien 2005

Authors and Affiliations

  1. 1.Department of Civil and Environmental EngineeringLouisiana State UniversityBaton RougeU.S.A

Personalised recommendations