Studies on fatigue strength evaluation of drag link assemblies used in automobile vehicles
Drag link assembly is a crucial component in various passenger and carriage vehicles, which connects the steering wheel to the front wheel of the vehicle which turns when the steering wheel rotate. Major care is taken during manufacturing for its rigidity, wear resistant and for exact angular fitment. However, experimental investigations on these components are essential for validation purpose. Totally 28 drag link assemblies were studied for fatigue life evaluation in seven categories. The total length of the drag links varies from 759 mm to 1605 mm for various types of linkages. During the test, the maximum and minimum loads, displacement and the number cycles were monitored continuously. Throughout the tests on various linkages, the specimens were visually observed at regular intervals of loading for possible crack initiation/failure. The failure of the linkages was noticed by identifying a crack/fracture either in the tube or ball joint and the corresponding number of cycles and location of the crack were recorded for all the specimens.
