A modified nonlinear damage accumulation model for fatigue life prediction considering load interaction effects.

Area of Science:

• Mechanical Engineering
• Materials Science
• Structural Engineering

Background:

• Variable amplitude loading is common in engineering structures.
• Accurate fatigue life prediction relies on effective fatigue damage accumulation models.
• Existing nonlinear models fail to account for load interaction effects, leading to significant errors.

Purpose of the Study:

• To propose a modified nonlinear damage accumulation model that incorporates load interaction effects.
• To validate the proposed model using experimental data from metallic materials.
• To compare the proposed model's accuracy and efficiency against existing models and Miner's rule.

Main Methods:

• Development of a modified nonlinear fatigue damage accumulation model.
• Validation using experimental fatigue data from two metallic materials.
• Comparative analysis with a primary nonlinear model and Miner's rule.

Main Results:

• The proposed model accurately predicts fatigue life under variable amplitude loading.
• Model predictions show better agreement with experimental data compared to existing models.
• The modified model effectively accounts for load interaction effects.

Conclusions:

• The proposed model offers improved accuracy for fatigue life prediction in engineering applications.
• It is suitable for predicting the fatigue life of welded aluminum alloy joints in Electric Multiple Units (EMUs).
• The model provides a balance between accuracy and computational simplicity, requiring fewer material parameters than existing methods.