Constitutive Model for the Thermo-viscoplastic Behavior of Hexagonal Close-Packed Metals with Application to Ti–6Al–4V Alloy
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In this paper, a new physically based constitutive model is developed for hexagonal close-packed metals, especially the Ti–6Al–4V alloy, subjected to high strain rate and different temperatures based on the microscopic mechanism of plastic deformation and the theory of thermally activated dislocation motion. A global analysis of constitutive parameters based on the Latin Hypercube Sampling method and the Spearman’s rank correlation method is adopted in order to improve the identification efficiency of parameters. Then, an optimal solution of constitutive parameters as a whole is obtained by using a global genetic algorithm composed of an improved niche genetic algorithm, a global peak determination strategy and the local accurate search techniques. It is concluded that the proposed constitutive modal can accurately describe the Ti–6Al–4V alloy’s dynamic behavior because the prediction results of the model are in good agreement with the experimental data.
KeywordsHexagonal close-packed metals Physically based constitutive model Dislocation motion High strain rate Ti–6Al–4V
The authors gratefully acknowledge the financial support by the National Natural Science Foundation of China Academy of Engineering Physics and the jointly set-up “NSAF” joint fund under Contract No. U1430119.
- 6.Arsecularatne JA, Zhang LC. Assessment of constitutive equations used in machining. Key Eng Mater. 2004;274–276:277–82.Google Scholar
- 12.Zerilli FJ, Armstrong RW. Constitutive equation for HCP metals and high strength alloy steels. In: Rajapakse Y, Vinson JR, editors. High strain rate effects on polymer, metal and ceramic matrix composites and other advanced materials. San Francisco: ASME International Mechanical Engineering Congress and Exposition; 1995. p. 121–6.Google Scholar
- 22.Sheng Y, Zeng XG, Han TX, Chen J. Parameter sensitivity analysis and identification method for dynamic constitutive relationship of titanium alloy. J Sichuan Univ. 2015;47:110–7.Google Scholar
- 23.Simpson TW, Lin DKJ. Sampling strategies for computer experiments: design and analysis. Int J Reliab Appl. 2001;2(3):209–40.Google Scholar
- 24.Sheng Y, Yi Y, Wei Y. An improved genetic algorithm of fast realization in multimodal function optimization. J Southwest Univ Sci Technol. 2009;24:85–90.Google Scholar