Innovative Methodology for Durability Evaluation of Off Road Vehicle Rear Axle under Bi-Axial Load Condition using Single Linear Actuator

Rear axles are subjected to bending and torsion loads out of which Bending loads are predominant. In case of Off road vehicles Bi Axial- combination of Bending and torsion loads were predominant, because of axle construction and vehicle usage pattern. Defined test procedures are available for bending durability and torsional durability evaluation of axles. In this experiment, new test methodology was developed for Bi Axial durability evaluation of Off road vehicle rear axle with single servo hydraulic linear actuator. For creating Bi Axial load condition, we may need multiple actuators and complicated fixtures. Axle wheel end is constrained at an angle with suitable fixtures for creating the bending and torsional forces together in the axle. Servo hydraulic linear actuator with suitable loading arm is used for applying the test torque in the axle input flange. Vehicle parameters like Engine torque, wheel reaction, axle ratio and wheel static loaded radius (SLR) etc., used for arriving the test specification. Strain gauging (Rosette) and data acquisition techniques are used for ensuring the proper load transfer to the axle. Data acquired in Bending, torsion and Bi-Axial (bending cum torsion) load condition. It is evident from the strain data with the newly developed test methodology Bi axial load condition was simulated in the axle. Endurance test of axle assembly was carried out with the new test methodology for validating the test method and identifying the failure modes.

The benefits of this exercise include:

1. 1
   Bi-Axial Torsion-Bending load condition created using a single actuator and with the help of simple fixtures.
2. 2
   Test methodology developed for Bi-Axial Torsion-Bending durability evaluation.
3. 3
   Strain Gauging and data acquisition techniques effectively used for test methodology comparison/Validation.