UNIFIED HARDENING MODEL AND DISLOCATION DYNAMICS ANALYSIS FOR MULTI-SHAPE OBSTACLE HARDENING

The interaction between dislocations and radiation-induced defects results in an increase in material yield strength, a phenomenon known as radiation hardening. This study introduces a unified model for predicting the critical resolved shear stress (CRSS) caused by impenetrable defects of arbitrary shapes.The paper begins by reviewing the commonly used spherical obstacle hardening models, such as the Bacon-Kocks-Scattergood (BKS) hardening model, discussing their limitations when applied to defects with complex geometries. It then utilizes dislocation dynamics simulations combined with linear elasticity theory to investigate the interaction between dislocations and obstacles of various shapes, including spherical, ellipsoidal, and cubic. Based on these findings, a unified hardening prediction model is developed that incorporates the geometric configuration of obstacles. The results show that the predictions of the unified hardening prediction model are in agreement with those from dislocation dynamics simulations and effectively capture the coupled hardening effects of obstacles with different shapes. This work enhances existing hardening models and improves the accuracy of radiation-induced material property predictions, offering valuable insights for the design of radiation-resistant materials.