Fatigue -and intelligent composites for sustainable structural health monitoring

Purpose and goal

The project aims to increase the understanding of how mechanical and thermal fatigue reduces the service life of composite and sandwich structures in transport applications, such as train fronts. The effect of combined thermal and mechanical loads that occur at high speeds in tunnels, for example, is difficult to predict, which leads to early breakdowns. New methods for structural monitoring will be used, which aim to increase knowledge of material degradation but also validate and establish new material systems, calculation methods and measurement techniques.

Expected effects and result

The project leads to increased knowledge about how composite and sandwich materials are affected by combined loads. The studies lead to improved dimensioning methods, thereby, more robust constructions and efficient use of the material, i.e. less material waste. In addition to traditional composite materials, a new type of bio-based fibre will be studied, which lays the foundation for the establishment of C02-neutral materials in fatigue-loaded structures. Furthermore, new technology for structural health monitoring will be further developed and made available.

Planned approach and implementation

The project uses embedded sensors to measure the strain inside the material. The proposed health monitoring system relies on fiber optics and carbon nanotube sensors to distinguish between thermal and mechanical loads. The sensors are made of the same material as the composite component, which simplifies future recycling. The work is done in collaboration with a Swiss company that manufactures train fronts, which also provides information on expected load cycles and suitable material systems. The Det Schweiziska project also develops the calculation methodology.