Structural Integrity Assessment Through Eigensolution

The paper discusses the employment of eigensolutions of finite element structural models as a tool to assess airframe structural integrity. It is aimed at the aviation technical manager with a general tertiary background, thereby including development from first principles of fundamental concepts required for the derivation and application of an inverse correlation technique. Consideration of the physical and mathematical properties of structural eigensolutions indicates this technique's potential to provide a global assessment of the structural integrity of structures representative of simplified aircraft wings for which finite element structural models exist or can be developed. A proof of concept study has applied the technique to beam element analytical models of varying degrees of freedom, correlated with preconditioned analytical complete modal sets, providing an indication of the method's effectiveness in locating small changes in elemental stiffness representative of structural fatigue.