Every modern brake manufacturer is compelled to meet stricter requirements with time constraints during development of safety related components "Brakes". The design is required to be taking in to account the cumulative damage caused to the part in the service load condition. Damage accumulation will lead to cause fatigue failure over a period of time. Durability design and analysis are important elements to achieve these objectives. To evaluate fatigue life of brake caliper parts, with use of service load histories and laboratory test data by forming suitable hypothesis. This will enable evaluating product liability, matching test loads to field loads, evaluating the risk and improving the shape of highly stressed parts. To develop S-N curve for brake carrier and know about the failure pattern of caliper carrier component fatigue test has planned in high frequency Resonator rig at various load levels (g levels).Ref fig:1 for SN curve.
It is planned to formulate a procedure for fatigue life prediction of a component using strain energy density based approach. The nature of brake carrier loading is in high cycle regime. In the strain energy density based method, the plastic strain energy density is used to evaluate no of cycles to failure in low cycle fatigue regime. For high cycle fatigue regime, the amount of plastic strain is small. So plastic strain energy density for life prediction in high cycle application is difficult. Total strain energy density comprised of both elastic and plastic strain energy density is used for calculating high cycle fatigue life.
Linear static analysis (FEA) on brake carrier was completed (Fig: 2). Critical parameter has to be evaluated from the analysis to apply for fatigue models.
- single ball simulation (with and without plasticity)
- multi-ball simulation with different combination of ball impacts (with and without plasticity)