Reduction of Dynamic Response of a Wind Tunnel Sting Mount Using Passive Damping

Dynamic response of wind tunnel mounts can cause difficulties with quality of test data, timescales of production testing and tunnel safety. Development is proposed of a wind tunnel sting mount with internal passive damping which will reduce sting vibration response to transient disturbances, leading to improved data quality and wind tunnel operations. The method proposed for adding passive damping is to introduce layers of viscoelastic damping material within the sting structure. As the sting distorts in its vibration modes the shear forces generated in the damping material reduce the dynamic response of the sting. The passive damping treatment can be applied to steel stings, but it is proposed that a better solution is to use composite material, which will have similar static stiffness and modal frequencies to the equivalent steel sting. Other questions arising from the use of composite material will be addressed in the research program. Phase I is aimed at establishing basic feasibility of the concept and applying it to a specific wind tunnel sting mount selected for this project. Phase II will extend the research into a more detailed evaluations, including failure modes and actual prototype testing, in laboratory tests and in a wind tunnel environment.