[1B2] Structural health monitoring considerations of self-drilling, self-tapping screws in saline environments
G McMeekin
Glasgow Caledonian University, UK
Fasteners form a crucial element in structural connections and, in saline environments, the monitoring of the rate of corrosion forms an important element in structural health monitoring. There is an increasing demand for fasteners, and their coatings, to perform in increasingly demanding environments due to climate change; however, the performance quantification is lacking and there is a gap in knowledge of structural health monitoring. This inevitably leads to the question of whether current coating technology is capable of efficiently performing in saline environments at elevated temperatures without significant loss of mechanical strength.
In this research study, the changes to structural health considerations are explored from the perspective of tensile resistance, shear resistance and coating wear on self-drilling, self-tapping fasteners in saline environments. Corrosion testing was performed pursuant to BS EN 9227:2022, tensile resistance was performed in accordance with BS EN ISO 6892-1 and shear resistance was performed in accordance with MIL-STD-1312-13.
The results show a negligible effect of corrosion exposure length on the mechanical properties of the fasteners in the short term, due to the effects of the geometry of fasteners. There was a relationship established between the rate of corrosion and the time exposed to the corrosive environment, with the more susceptible zinc coating being affected at a faster rate than the carbon steel that the fastener is made from. These results highlight the need for proper maintenance procedures and the requirement for longer-term observations where the fasteners’ geometry issues due to loss of material are overcome.
In this research study, the changes to structural health considerations are explored from the perspective of tensile resistance, shear resistance and coating wear on self-drilling, self-tapping fasteners in saline environments. Corrosion testing was performed pursuant to BS EN 9227:2022, tensile resistance was performed in accordance with BS EN ISO 6892-1 and shear resistance was performed in accordance with MIL-STD-1312-13.
The results show a negligible effect of corrosion exposure length on the mechanical properties of the fasteners in the short term, due to the effects of the geometry of fasteners. There was a relationship established between the rate of corrosion and the time exposed to the corrosive environment, with the more susceptible zinc coating being affected at a faster rate than the carbon steel that the fastener is made from. These results highlight the need for proper maintenance procedures and the requirement for longer-term observations where the fasteners’ geometry issues due to loss of material are overcome.
