Aerodynamic performance of spiral-protuberance cable under rain and dry conditions

Abstract

Aerodynamic control methods for rain-wind-induced vibration (RWIV) have been developed so far. However, it is pointed out that these methods are still defective. For example, indented surface type is effective for RWIV but not for dry galloping (DG). Therefore, it is urgent to develop an effective countermeasure which can be applied for both RWIV and DG. In this study, responses of cables with spiral protuberances together with smooth surface, parallel protuberances and indented surface are examined in rain and dry conditions. The results reaffirmed that RWIV and DG only occurred in specific conditions and limited vibrations still appeared in indented surface and parallel protuberances. More importantly, the test indicated that the spiral protuberance with 4, 6 or 12 fillets at certain winding angle and pitch can mitigate totally RWIV and DG compared to indented surface and parallel protuberance types.