PSI - Issue 71

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ScienceDirect

Procedia Structural Integrity 71 (2025) 461–468

5 th International Structural Integrity Conference & Exhibition (SICE 2024) A CPFEM based 3D Model for Polycrystalline Plasticity with Diffused Grain Boundaries

Ayub Khan * , A Shivnag Sharma, Pritam Chakraborty

Department of Aerospace Engineering, IIT Kanpur, Kanpur, UP -208016, India

Keywords: Crystal plasticity; Diffused interface; Microstructure; Polycrystals; Geometrically necessary dislocations 1. Introduction Polycrystalline materials constitute a cornerstone of engineering, finding widespread applications in critical industries such as aerospace, automotive, and structural engineering. Their versatility arises from a combination of desirable mechanical properties, including strength, ductility, and toughness, making them indispensable for various structural and functional components. However, unlocking the full potential of these materials necessitates a deep understanding of their intricate microstructural characteristics and their influence on macroscopic behavior (Asaro and Rice (1977). Abstract Understanding the relationship between the microstructure of polycrystalline materials and their macroscopic properties is critical for developing and improving them for advanced applications. In polycrystalline aggregates, the combination of computational homogenization and crystal plasticity has shown promise in simulating the effective properties and capturing such correlations. Our study uses a similar framework to model polycrystals with FCC and BCC crystal structures. The goal is to investigate the plastic deformation behavior of these materials, specifically focusing on the role of Geometrically Necessary Dislocations (GNDs). We employ a phenomenological Crystal Plasticity (CP) model on a cubic Representative Volume Element (RVE). The simulations capture the effect of crystallographic orientations, grain boundaries, and dislocation mechanisms on the deformation of polycrystalline RVE. To account for the complex behavior at grain boundaries, a diffused interface model is proposed. This model homogenizes the deformation behavior within the grain boundary region to capture more effectively the hardening due to dislocation pile-up, providing a more realistic representation of the interaction between grains. Our findings provide insights into the influence of grain boundaries on the overall strain hardening and deformation response of polycrystalline materials. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SICE 2024 organizers

* Corresponding author. Tel.: +91-8791082898.

E-mail address: ayubk21@iitk.ac.in

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SICE 2024 organizers 10.1016/j.prostr.2025.08.062