Aircraft Airworthiness & Sustainment Conference

BEASY staff attended the 2015 AA&S Conference in Baltimore in April and met with many customers to discuss their applications and update them about projects underway at BEASY.  

We had a lot of new interest at our booth this year in the areas of fatigue crack growth in residual stress fields, fracture behaviour of composite plates as well as the modelling of corrosion related damage. There was also considerable interest in the BEASY Corrosion Manager software which is used to predict and simulate galvanic corrosion in structures such as aircraft.

Cold worked hole fracture May 15 edited

Of particular interest was the impact of residual stresses on the crack path and the rate of growth of cracks. The effect on the crack path can be clearly seen in the above figure where the lines show the predicted crack fronts as the crack grows from a hole with, and without, cold working. The red lines show the predicted crack fronts without cold working and the green dotted lines show the predicted crack fronts with cold working. The study clearly indicates the need to include residual stresses in crack growth calculations as otherwise unexpected failure modes can occur, and excessively conservative designs can result.

Please contact us for background papers on some of the topics presented at AA&S 2015, quoting the name(s) of the papers below:

Analysis of Fatigue Crack Growth for CFRP-Strengthened Steel Plates with Longitudinal Weld Attachments

Analysis of CFRP reinforced steel plates

Analysis of fatigue crack growth for welded connections under bending

Calculation of bending fatigue life of thin-rim spur gears

Analysis of fretting fatigue life of dovetail assemblies based on fracture mechanics method

Another area of considerable interest at the AA&S conference was the use of computer simulation to assess the risks associated with corrosion. During the product development process, various design configurations are often exposed to actual environmental conditions for an extended period of time to evaluate corrosion damage in the structural assembly. However, these testing methods require anywhere from several months to several years of exposure time in order to complete. Computer modelling has the potential to significantly shorten, and reduce, the cost of testing by providing a corrosion simulation option that can be used to supplement these long term experimental tests.

Galvanic Stack Up model fracture1 May 15 edited

In the model shown a computer simulation is used to predict the risk and extent of corrosion damage on a test structure.