Improved analysis capability and strength properties of bolted joints in advanced metal-composite structure

Important results from the project

The project goal was to develop experimental methods and analytical models for evaluation, measurement and prediction of strength and flexibility of hybrid metal/composite bolted structures. Besides that, techniques for reinforcements of bolt holes in composite plates, with interlacement of metal inserts and with thin ply laminae, have been developed and their effect on strength evaluated.

Expected long term effects

The optical measurement method (DIC) of bearing damage in composite and of elastic material properties was demonstrated and a method for measurement of flexibility of bolt installations. Prediction models of bearing failure were developed and validated by experiments and the methods for hole reinforcement in composite showed potential increase the strength of the composite. The results will benefit the industry by improvement of sizing methods, modelling technique, testing and reinforcement techniques. The measurement methods are available for future research projects.

Approach and implementation

The project was performed as a cooperation between the aircraft industry (SAAB), the research institute (RISE), universities (LiU and KTH) and SMEs (Oxeon AB och Image Systems). Two PhD students were active in the project and one of them graduated during the project.