Correlation Study of the UH-1B Helicopter Blast Test Results from the DICE-THROW Event

This report summarizes the results of a correlation study conducted in conjunction with the UH-1B helicopter blast test during the DICE THROW event. The processed structural and motion response data from the hovering and droned helicopter are presented. They are correlated with corresponding analytical predictions based primarily on the helicopter code HELP and the aircraft structural code NOVA-2. The monitored blast-induced responses include 1 The flapwise bending moments and the flapping angles of both the tail and main rotor blade systems 2 The lateral bending moments at two fin and two tail boom stations 3 The overall rigid-body motions of the vehicle consisting of the altitude variations, the attitude and angular rate variations in the yaw, pitch, and roll degrees-of-freedom and 4 The strains at selected points on a tail boom panel, a stiffener, and a longeron. Considering the qualities of the available input data for the analyses and of the measurements, the experimental results are generally in reasonable agreement with the predictions from the HELP code. The NOVA-2 predictions for panel, stiffener, and longeron strains fare poorly when compared with experiment. In some instances, significant differences are found between experiment and analysis. Whenever possible, the reasons for the disagreements are identified and discussed.