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Any analysis tool should be validated to verify computation accuracy. Fatigue analysis processes are inherently complex to validate due to the sensitivity and interdependency of variables. In the current work the authors systematically separate the variables for independent evaluation and verification. The approach is the result of new Neuber notch analysis equations, derived by the authors, and draws upon the experience of the authors as well as several other analysts in developing an approach that reduces interaction between variables. The extension of the Neuber’s Rule into multiaxial format is presented. Each building block of the process is discussed: loads and load histories, stresses, stress concentrations, notch analyses (uniaxial and multiaxial), material properties (stress-strain response as well as life data), and damage accumulation. A method to account for fretting is discussed. Occasionally, during an evaluation, a variable is either overlooked or not quantified well.

Flexible airplane structures in the presence of excitation forces may oscillate with bounded or unbounded motion. Vehicle safety and durability depend on control and reduction of this vibration. Designers can generally safeguard against its occurrence by tuning the airframe. Supplementing the design function are experimental studies that identify and verify dynamic response characteristics for aeroelastic and fatigue considerations. This paper will discuss an experimental methodology which is based on fundamental engineering principles and basic laboratory instrumentation. Examples are included in an attempt to demonstrate the directness and efficiency obtainable.