The research on the skew force caused by skew operation of bridge cranes

Abstract

Skewing of the bridge crane during actual operation occurs due to various reasons. This phenomenon leads to collisions between the guiding devices (guiding rollers or flanges) and the rails, generating the skew forces. With the development of the industry, cranes are becoming larger and heavier, making the issue of wheel-rail wear during skew operation of bridge cranes more prominent. In addition, the skew force is an important factor in evaluating the crane’s turning performance. So, the accurate calculation of skew force not only improves the design accuracy of the bridge crane, but also lays the foundation for future research on crane turning dynamics. Different standards provide varying methods for calculating it, yet the skew force is difficult to measure through actual experiments. Therefore, comparing the actual skew force with theoretical calculation results remains a challenge. In this manuscript, a dynamic model of the bridge crane with skew operation due to unsynchronized drives on both sides is established by replacing independent wheel with traditional wheelset. The wheel-rail relationship during the skew process is analyzed based on simulation results. By comparing the skew forces obtained from two theoretical calculation methods and simulation experiments under different conditions, it is found that the theoretical calculation results are consistently higher than the simulation results. The coefficient method neglects some influencing factors and conservatively calculates the skew force. The polar moment method treats the wheels and rails as ideal rigid bodies, ignoring the effects of local deformations.