Aging aircraft structures require safe and damage-tolerant repair techniques. Instead of using conventional riveted repairs, bonded repairs can be a more viable solution. Adhesive bonding provides a more uniform and efficient load transfer into the patch, and can reduce the risk of high stress concentrations caused by riveted repairs. Delft University of Technology and the United States Air Force Academy run a joint research project into bonded patch repair. One aspect of this research is the investigation into thermal (residual) stresses arising under and around bonded patch repairs due to the adhesive cure cycle and aircraft operating temperatures. These thermal (residual) stresses can either be beneficial or detrimental. It is therefore of prime importance that these stresses and the variables of influence are known, and can be predicted (and thus designed for). Over the course of years the project has been running, the analytical model used to predict the thermal stresses in the repaired region showed the need for careful review and updating. Mistakes in the original derivation were corrected and temperature distributions derived anew. Comparison of the updated model with other analytical or finite element models showed good agreement for temperature distributions and predicted thermal stresses, although comparison with experimental results is as of yet difficult due to out-of-plane deflection of the specimens.
Thermal stresses in aircraft structures repaired with bonded patches
2004
15 Seiten, 13 Quellen
Aufsatz (Konferenz)
Englisch
Analysis of Cracked Aluminum Plates Repaired with Bonded Composite Patches
Online Contents | 1996
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British Library Conference Proceedings | 1995
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