Fatigue Life Assessment of Welded Chassis Frame Joints
Fatigue Life Assessment Approaches Comparison Based on Typical Welded Joint of Chassis Frame
Fatigue failure remains one of the major causes of damage in welded steel structures. For this reason, accurate fatigue life assessment is particularly important for structures subjected to repeated cyclic loading.
This study compares several fatigue life assessment approaches using a typical welded joint of a chassis frame as the reference case. The investigated methods include the Nominal Stress approach, Hot Spot Stress approach, Notch Stress approach and Fracture Mechanics approach.
The calculated fatigue life obtained using these methods is compared with experimental fatigue test results. This comparison makes it possible to evaluate the accuracy and practical applicability of each assessment method and identify the approaches that provide the closest correlation with experimental data.
Introduction
Fatigue damage is one of the principal failure mechanisms affecting welded structures subjected to cyclic loading. Welded joints are particularly sensitive to fatigue because local stress concentrations, weld geometry, imperfections and residual stresses can significantly influence crack initiation and propagation.
A number of different methods are available for evaluating the fatigue life of welded structures. These methods differ in complexity, required input data and the way local stresses and weld geometry are represented.
In this study, four fatigue assessment approaches are investigated and compared using the same welded joint configuration:
- Nominal Stress approach
- Hot Spot Stress approach
- Notch Stress approach
- Fracture Mechanics approach
The results obtained from the analytical and numerical calculations are compared with experimental fatigue test data in order to evaluate the accuracy of the different approaches.