Failure Mode Effect and Criticality Analysis of Stub Axle...

Failure Mode Effect and Criticality Analysis of Stub axle subassembly 1. Introduction: FMECA is a methodology to identify and analyse predicted failure modes of various parts within the assembly or system. It is a technique to resolve potential problems in a system before they occur. It is most widely used reliability analysis technique performed between the conceptual and initial stage of the detailed design phase of the system in order to assure that all the potential failures have been considered and the proper provisions have been made to eliminate these failures. [1] (Ref. system reliability theory,2nd edition, Marvin Rausand) this technique can assist in selecting alternative concept for the same system and also provide†¦show more content†¦The outer racer of the bearing is fastening into the boss. The whole subassembly is then attached with the steering arm, stub axle by means of welded joints and the plate welded to the chassis by means of Rod end bearing(2). The steering arm is joined with the steering rod by swivel joint as shown in the fig1. By going through the force diagram2 of the system below, the number of components those are highly stressed and because of which may fail or lack in desired performance is four. i. Stub axle: stub axle whose main function is to be a hostage of the wheel may be deformed due to high fatigue stress induced due to the repetitive compressive load on upper edge and tensile on lower edge as many times as the wheel experiences high impact load in upward direction. And the result is the difficulty while cornering. Even though the probability of failure of stub axle is higher due to impact failure of weld joints. Which may cause the serious safety effect. ii. Hose and Bearing subassembly: As its main function is to reduce the friction, and providing bearing support, its conceivable failure is detected by testing during maintenance. the probability of failure is either wearing off the rolling element, or misalignment of bearing which is a result of failure of bearing spacer. The system effect due to this is difficulty in cornering the vehicle, harsh