Aircraft taxiing dynamic load induced by runway roughness

Abstract

In order to explore the effect of runway roughness and taxiing speeds on dynamic loads, ADAMS/ Aircraft software was used to establish a virtual prototype model of B737-800, reconstructed runway profiles by the power spectral density method and simulated multiple conditions with a constant speed. Finally, a prediction equation of the maximum dynamic load coefficient was developed based on the relationship between the variance of runway roughness and the corresponding power spectral density. Results show that the increase of unevenness index (C) and waviness (w) increases the maximum dynamic load coefficient and the variability of dynamic load coefficient. Once the unevenness index ( C) increases to a certain level, the maximum dynamic load coefficient tends to be flat out, while the maximum dynamic load coefficient increases faster with the increase of waviness ( w ) . With the combined effects of runway roughness and lift force, the maximum dynamic load coefficient first increases and then decreases, resulting in an extremum and a corresponding sensitive velocity. The sensitive velocity increases with the increase of the unevenness index (C) and waviness (w) , and the effect of waviness (w) is more significant. The proposed prediction equation has a good correlation with the simulation results (R2> 0. 93 ) , and for most of the measured runways ( C = 0 -0.4,w = 2.0 -2.6) , the sensitive velocity is up to 150.4 km/h and the maximum dynamic load coefficient is 1. 163.