Final answer:
To estimate the bearing life for 90% reliability, we can use the Weibull distribution and the concept of cumulative damage contribution. The cumulative damage contribution for each load can be calculated using the Miner's rule.
Step-by-step explanation:
To estimate the bearing life for 90% reliability, we will use the concept of the Weibull distribution. The Weibull distribution is a probability distribution that is commonly used to model the reliability of mechanical systems. To estimate the bearing life for 90% reliability, we will use the following formula:
t = B * x^a
where t is the bearing life, B is a constant that depends on the type and quality of the bearing, x is the applied load, and a is a constant that depends on the reliability level.
We don't have the values of B and A in this case, so we cannot calculate the exact bearing life. However, we can estimate an approximate bearing life by using the average load and speed values for each load condition and assuming a constant value for B and A.
The cumulative damage contribution for each load can be calculated using the Miner's rule. The Miner's rule states that the total damage caused by a repeated load is the sum of the individual damage contributions for each load condition. The damage contribution for each load condition can be calculated by dividing the load duration by the expected bearing life for that load condition.