THE WORST DYNAMIC ICE FORCE ON NARROW CONICAL STRUCTURES

The failure modal effect is a dominant synthetic effect for dynamic ice forces on conical structures. It should be the transitional failure acted as the worst failure mode, which associated the worst ice force with the biggest peak, the most repeatable period and most sensitive to velocity. This hypothesis is proved by using one case study, four analytical models and one numerical model. Based on these, a dynamic ice-load function and its 3 parameters used for narrow conical structures are formulated. A calculating example shows that under the transition conditions, the predicted dynamic ice forces are closed to the measured ones.