PSI - Issue 32

A.S. Shalimov et al. / Procedia Structural Integrity 32 (2021) 230–237 Shalimov A.S., Tashkinov M.A. / Structural Integrity Procedia 00 (2019) 000–000

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presented in Figure 9. The absolute value for the applied loads for tensile and compressive curves do not differ much, but for the case of model with damage it is noticeable that the completion of the calculation due to the large number of elements with degraded properties occurs much earlier in compression.

Fig. 9. The loading curves for elastoplastic numerical models with the procedure of degradation of elastic properties of the same inclusion volume fraction with different load models.

When the individual ligaments have plastic properties and the strain is not redistributed to nearby ligaments, resulting in brittle material behavior. In both compression and tension numerical tests, specimens with smaller ligament diameters had a higher yield strength. Under compression nanoporous gold undergoes strengthening during the deformation process through pore compaction. 4. Conclusions The investigation of the deformation behavior of nanoporous metals, as well as the magnitude and location of the associated stress concentrations, remain relevant problem. In this article, geometric models of open-cell porous RVE with interpenetrating structure, simulating the structure of nanoporous gold, have been created. The calculation of stresses and strains fields in three-dimensional RVE is based on a continuum model taking into account parameters determined at smaller scales. The finite element method was used to perform numerical computations. Three material models were studied: an elastic model, an elastoplastic model and an elastoplastic model with the damage accumulation model implemented as the procedure of degradation of properties. The effect of the morphological structure and parameters on redistribution of stresses and occurrence of stress concentration zones in the matrix is investigated. It was demonstrated that random morphology can play as important role in determination of the mechanical behavior of the nanoporous structures as volume fraction of the porous phase. Acknowledgements The research was performed at Perm National Research Polytechnic University, with the support of Russian Science Foundation (project № 20 -79-00216). References

Bargmann, S., Soyarslan, C., Husser, E., Konchakova, N., 2016. Materials based design of structures: Computational modeling of the mechanical behavior of gold-polymer nanocomposites. Mech. Mater. 94, 53–65. https://doi.org/10.1016/j.mechmat.2015.11.008