Coarse-Grained Modeling and Interpretation of Phenomenological Creep Rate Behavior with Experimental Validation

Area of Science:

• Materials Science
• Statistical Physics
• Mechanical Engineering

Background:

• Creep is a primary failure mechanism in materials at high temperatures.
• Existing creep models lack a unified physical explanation for the characteristic bathtub-shaped creep rate curve.
• The physical origin of creep damage evolution and its stages remains unclear.

Purpose of the Study:

• To develop a physically interpretable hierarchical model for creep damage.
• To provide a unified description of primary, secondary, and tertiary creep stages.
• To offer a theoretical explanation for the bathtub-shaped creep rate curve based on statistical physics.

Main Methods:

• Treating creep damage as an aging failure process in a material system.
• Establishing a hierarchical model based on statistical physics for disordered complex systems.
• Linking microscopic material unit evolution and interaction to macroscopic creep behavior.

Main Results:

• The proposed model unifies the description of the three-stage creep process.
• A theoretical explanation for the bathtub-shaped creep rate curve is provided.
• Validation with metallic and composite materials shows reasonable reproduction of full-process creep behavior (RSS: 1.3088 and 0.5369).

Conclusions:

• The model offers a physically interpretable, unified framework for creep behavior.
• It provides a statistical perspective on creep degradation mechanisms.
• Further validation and comparison with conventional methods are needed for broader applicability.