This paper presents a coordinated effort to model, test and validate the structural response of complex aerospace rib-skin structures in both undamaged and damaged configurations. Coordinated experimental and finite element model results are presented for cylindrical rib-skin structures each approximately nine foot long, and thirty inches in diameter. The test articles considered are of riveted...

The use of ultrasonic signals at sub-MHz frequencies for Non Destructive Evaluation of thick polymer samples is described. It will be shown that the combination of low-frequency coded signals such as chirps, together with appropriate signal processing methods such as pulse compression, can provide a powerful tool for ultrasonic NDE. To achieve this goal, it is essential that the measurement sys...

Enhancement in fatigue performance of welded joints by Ultrasonic Impact Treatment (UIT) was evaluated with large-scale rolled beam and built-up specimens having yield strength of 345 to 760 MPa. Eighteen rolled-beam specimens having welded details at cover plates and transverse stiffeners and eight built-up specimens having only transverse stiffener details were fatigue tested after treating t...

In the present work, the survivability of a submerged structure against loads, imposed by the operational environment, such as hydrostatic pressure is presented. The structure under consideration is a component (buffer bell) of a system called DIFIS that recovers fuel from shipwrecks. It consists of two parts: the reservoir and the floater. The floater is the part that produces the buoyancy for...

A dispersion of stiff and thin (‘rigid line’) inclusions (RLIs) in a matrix material may result beneficial for stiffening the elastic range, but might be detrimental to strength, as instabilities triggered by when is brought viscoplastic-damaging state. This dual role RLIs investigated means embedded reinforcement model. Validated against available analytical predictions, this numerical model e...