Fatigue Life Prediction of TC4 Titanium Alloy Bolted Structures in Thermal Environments Below 400 °C Using an...

Area of Science:

• Materials Science
• Mechanical Engineering
• Aerospace Engineering

Background:

• TC4 titanium alloy bolted structures are critical in aerospace, especially in aircraft engines.
• Existing fatigue life prediction methods are insufficient for moderate elevated temperatures (up to 400°C).

Purpose of the Study:

• To develop an enhanced detail fatigue rating (DFR) method for TC4 titanium alloy bolted structures under thermal conditions up to 400°C.
• To improve the accuracy of fatigue life prediction in moderate temperature environments.

Main Methods:

• Acquired fatigue life data for TC4 titanium alloy at 20°C, 200°C, and 400°C.
• Developed an enhanced DFR method incorporating temperature-dependent thermal effects.
• Applied the enhanced DFR method to predict fatigue life of double-shear TC4 bolted structures.

Main Results:

• The enhanced DFR method demonstrated improved fatigue life estimation accuracy.
• Average fatigue life estimation accuracy increased by 9.29% compared to the conventional DFR method.
• The proposed method shows high promise for evaluating fatigue performance within the 20-400°C range.

Conclusions:

• The enhanced DFR method provides a more accurate tool for predicting the fatigue life of TC4 bolted structures at moderate elevated temperatures.
• This advancement is crucial for ensuring the safety and reliability of aerospace components operating in thermal environments up to 400°C.