Here is my problem:
We make split, babbitted bearings for our customer. The wall of the bearing is approximately, 3/8" thick and after splitting it, there is a "free spread" dimension on the print that is to be met. If the part is not at this free spread dimension, the bearing half is "sprung" to size (basically we manually deform it to meet the drawing requirement.) The problem is that these are repair/replacement parts and that while they conform to the drawing dimensions at the time they are made, and would conform to the mating housing into which they are going, but our customer shelves them for when they need them, and after time, the part relaxes so that the free spread dimension is oversized when pulled off the shelf.
So my question is this: Is there a way to estimate the amount of stress relaxation a part will endure over time, such as a time/stress curve, for a particualr material. We cannot run the parts thru a stress relief cycle because it would result in melting out the babbitt.
We make split, babbitted bearings for our customer. The wall of the bearing is approximately, 3/8" thick and after splitting it, there is a "free spread" dimension on the print that is to be met. If the part is not at this free spread dimension, the bearing half is "sprung" to size (basically we manually deform it to meet the drawing requirement.) The problem is that these are repair/replacement parts and that while they conform to the drawing dimensions at the time they are made, and would conform to the mating housing into which they are going, but our customer shelves them for when they need them, and after time, the part relaxes so that the free spread dimension is oversized when pulled off the shelf.
So my question is this: Is there a way to estimate the amount of stress relaxation a part will endure over time, such as a time/stress curve, for a particualr material. We cannot run the parts thru a stress relief cycle because it would result in melting out the babbitt.