| Περίληψη: | The main objective of this thesis is to develop the scientific and technological frame that will issue validated design rules for rotor blade repair, mainly driving the outline of this manuscript. Firstly, a literature survey is undertaken to present an overview of the development of adhesive joint modelling. Adhesive joints have been investigated over the past 70 years and an outline of the numerous analytical and numerical models, that have been developed, is presented here. The area of structural bonded repair of composites is briefly reviewed as well.
The second part introduces a comprehensive test campaign, including adherend and adhesive material characterization, which is undertaken in order to investigate repair patching efficiency. Experiments on bonded coupons are designed to study several joint parameters and bonding techniques used in the rotor blade repair industry.
The third goal is to meet the problem of predicting the behaviour and strength of adhesive joints. A modelling procedure for simulating adhesive joint behaviour is presented. Degradation models, simulating damage propagation, without predefining the failure path, are introduced for both composite adherends and polymeric adhesives. Material nonlinearity of the adherends is also implemented, while the presented softening procedure accounts for energy dissipation during debonding.
Last part of this work includes the modelling and experimental validation of a real-world implementation of adhesively patching a defect rotor blade. The effect of the defect on the residual strength of the blade is investigated and the optimal repair design is performed. Finally, full scale test of the rotor blade sub-component is performed to validate the repair design.
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