Phase-Field Model for SMA Fracture and Fatigue
Analysis
This paper introduces a new computational model for simulating fracture and fatigue in shape memory alloys (SMAs). The model combines phase-field methods with existing SMA constitutive models, allowing for the simulation of damage evolution alongside phase transformations. The key innovation is the introduction of a transformation strain limit, which influences the damage localization and fracture behavior, potentially improving the accuracy of fatigue life predictions. The paper's significance lies in its potential to improve the understanding and prediction of SMA behavior under complex loading conditions, which is crucial for applications in various engineering fields.
Key Takeaways
- •Proposes a novel variational phase-field model for fracture and fatigue in pseudoelastic shape memory alloys (SMAs).
- •Couples damage evolution with phase transformation, building upon existing SMA constitutive models.
- •Introduces a transformation strain limit that influences damage localization and fracture behavior.
- •Demonstrates promising agreement with experimental fatigue life data for Ni-Ti multi-wire samples.
- •Enables discrimination between safe and critical loading scenarios.
“The introduction of a transformation strain limit, beyond which the material is fully martensitic and behaves elastically, leading to a distinctive behavior in which the region of localized damage widens, yielding a delay of fracture.”