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Mitigating Crack Propagation In A Highly Maneuverable Flight Vehicle Using Life Extending Control Logic, Mohamed Mostafa Yousef Bassyouny Elshabasy

Mechanical & Aerospace Engineering Theses & Dissertations

In this research, life extending control logic is proposed to reduce the cost of treating the aging problem of military aircraft structures and to avoid catastrophic failures and fatal accidents due to undetected cracks in the airframe components. The life extending control logic is based on load tailoring to facilitate a desired stress sequence that prolongs the structural life of the cracked airframe components by exploiting certain nonlinear crack retardation phenomena. The load is tailored to include infrequent injections of a single-cycle overload or a single-cycle overload and underload. These irregular loadings have an anti-intuitive but beneficial effect, which has …