A State-Based Peridynamic Flexural Fatigue Model for Contact and Bending Conditions

Area of Science:

• Mechanical Engineering
• Materials Science
• Computational Mechanics

Background:

• Traditional fracture models struggle with complex crack initiation and propagation.
• Predicting fatigue life in mechanical components under cyclic loading is crucial for design and safety.
• Peridynamics offers a non-local approach suitable for fracture mechanics.

Purpose of the Study:

• To develop and validate an ordinary state-based peridynamic (PD) fatigue model for flexural fractures.
• To accurately predict the initiation and propagation of flexural cracks and estimate fatigue life.
• To demonstrate the model's capability in simulating crack evolution in gear contact scenarios.

Main Methods:

• Replaced traditional partial differential equations with a spatially integral peridynamic model.
• Utilized a nonlocal peridynamic contact algorithm based on contact and slip theory for load transfer.
• Employed 3D peridynamic J-integration and an energy-based bond failure criterion.
• Simulated fatigue crack growth in gear contact surfaces under repeated loading cycles.
• Applied an improved adaptive dynamic relaxation approach for static solutions per cycle.

Main Results:

• The peridynamic fatigue model accurately predicted crack initiation and propagation without additional criteria.
• Fatigue bending crack angle errors were within 2.92%, and cycle number errors were within 10%.
• Simulated fatigue life showed good agreement with experimental results for gear contact surfaces.

Conclusions:

• The proposed peridynamic fatigue model effectively addresses flexural fractures and predicts fatigue life.
• The integral nature of peridynamics provides a robust framework for simulating crack evolution.
• The model demonstrates high accuracy and reliability for predicting fatigue behavior in practical engineering applications.