A Constitutive Model for Polycrystalline U–Nb Alloy Considering Multiple Phase Transition. Issue 1 (1st November 2022)

• Record Type: Journal Article
• Authors: Liu, Tingyi
• Is Part Of: Crystal research and technology. Volume 58:Issue 1(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-01
• Subjects: constitutive modeling -- phase transitions -- reorientation -- shape memory effect -- U–Nb alloys; Crystallography -- Periodicals; 548
• DOI: 10.1002/crat.202200166
• Languages: English
• ISSNs: 0232-1300

Abstract

Abstract: This study proposes a thermomechanical constitutive model for the shape memory effect of U–12.8 at.% Nb (U–Nb) alloy. The phenomenological model uses two variables for transformation. A transitional evolution function based on dissipative force is constructed, which removes the consistency condition. This improvement leads to a natural smoothness of all transitions, without any specifically defined hardening function. In addition, hysteresis is a natural result of the same reference force being converted forward and backward, and defining two different mixing energies is not necessary. The effect of strain rate is captured in the same frame by a function of the transition coefficient. This paper designs a robust and efficient numerical algorithm for the ordinary differential equation system. The model is validated by several special load cases. The simulation results are then compared with previous experimental data in the paper. Abstract : This study proposes a thermomechanical constitutive model for the shape memory effect of U–12.8 at.% Nb (U–Nb) alloy. The model here realizes a natural smoothness of all transitions and hysteresis for phase transformation. The model is validated by several special load cases. The simulation results are then compared with previous experimental data in the paper.