Bonded composite patches have been successfully used to restore damaged metallic airframes in both military as well as civil aircrafts and this technique has been recognized as one of the most effective methods for increasing the durability and damage tolerance of the repaired structure. These repairs alter the load path, bridge the damage and reduce stress intensity factors thereby retarding damage growth. Although much work has been done in the design of such patches, an important area, which has been neglected, is the design of composite repair patches taking into account the effect of temperature.
The objective of this thesis is to analyze adhesively bonded composite patches for the repair of aluminum substrates subjected to thermal loads. The first paper included in this thesis presents the results of a parametric finite element analysis directed towards minimizing the thermal residual stresses present in the bonded composite repair. The second paper uses FEA to investigate the free-vibration and transient response of damaged substrate repaired by an adhesively bonded composite patch subjected to thermal loads.
This thesis attempts to understand the effect of temperature on the bonded composite repair. The study includes the use of FEA for designing over incumbent thermal residual stresses and outlines the effect of temperature on the bonded composite joint. By studying the effect of temperature on such adhesively bonded composite repairs this study hopes to remove some of the obstacles faced during the application of such techniques in the repair and life enhancement of aging aircrafts --Abstract, page iv
