Wind tunnel testing of FLexible Advanced aeroelastic Models of BRidGe cables

The project aimed to improve wind testing facilities and develop an experimental methodology for laboratory simulation and investigation of airflow conditions around cables with climatic and technological roughness in particular- the study of Wind Induced Vibrations (WIV) of bridge cables. Advanced flexible aeroelastic models with the closest possible representation of the real shape of the cables, including the characteristic shape of cables covered with glaze ice, spiral pattern of the helical strake, etc… allow to achieve higher natural modes (up to 4 and higher) with the ability to fine-tune natural frequencies for testing the realistic Reynolds number range, as well as ensuring the 3-dimensional nature of cable-wind interactions in controlled laboratory conditions. The project involves the use of the close to real cable diameter for the model (110 mm) as well as a large ratio of diameter to length (1:40). It is also necessary to have space for placing fastening and tensioning equipment and cables. Thus, key parameter required for carrying out the tests is a wind tunnel cross section where the model stand can be placed. Within the framework of the project, 2 models with different surface roughness were tested:

1. smooth model (as reference) ;
2. model of cable with asymmetrical ice accretions – this model was tested at 3 different angles of attack on the ice "edge".

The steel core pretension for both models was set at 2 levels tuned for the frequencies of first natural mode f = 5 and 10 Hz. All models configurations were tested at 2 orientations with yaw angles 0° and 15°.