SAE AIR5797

Description / Abstract: This SAE Aerospace Information Report (AIR) describes the current process for performing comparative wear testing on aircraft tires in a laboratory environment. This technique is applicable to both radial and bias tires, and is pertinent for all aircraft tire sizes.

This AIR describes a technique based upon "wear" energy. In this technique, side wear energy and drag wear energy are computed as the tire is run through a prescribed test program. The specifics that drive the test setup conditions are discussed in Sections 4 through 7. In general, the technique follows this process:

• A test profile is developed from measured mechanical property data of the tires under study.
• Each tire is repeatedly run to the test profile until it is worn to the maximum wear limit (MWL). Several tires, typically 5 to 10, of each tire design are tested.
• Wear energy is computed for each test cycle and then summed to determine total absorbed wear energy.
• An index is calculated for each tire design. This is accomplished by dividing the total linear inches of wear at the most worn point into the total wear energy.
• The indexes are then normalized to provide a comparative wear rate.

The described technique is not meant to provide an absolute wear rate or wear index because the technique does not produce results that allow the user to say a tire will last for a specific number of landings. However, it does provide a comparative index. It will make a distinction from one tire design to another by indicating a percentage difference in abrasive wear rate under representative operational conditions. The technique has been demonstrated in a number of test programs and is shown to have an extremely high correlation to field data. Supporting data is included in Section 9.