A Study of the Effect of Repeated Tension Impact Loads Upon Certain Metals Used in Aircraft Construction

The Impact Endurance Limit is evaluated for several materials used in aircraft construction. The Impact Endurance Limit is defined as the energy per blow in tension impact below which the specimen will withstand an indefinitely large number of blows without fracture. The effect of grain orientation on the Impact Endurance Limit is shown. Evidence is presented that the Impact Endurance Limit may be a function of the ultimate tensile strength but not of the elongation or the yield point. The effect of service stresses on the Impact Endurance Limit is discussed