As an essential part of the water conservancy hub, the miter gate undertakes the vital task of navigational operation and works in a complex basin with a high water level drop for a long time; therefore, it is necessary to ensure its safe operation. In this paper, taking the Gezhouba No. 2 ship lock miter gate as an example, the actual gate stress and crack signals are obtained using the online monitoring system. The stress distributions of the gate under different working conditions are studied using finite element simulation analysis. Combining simulation analysis with the collected signal analysis, the operation status of the actual gate under each working condition is evaluated. The results show that the stress analysis of the online monitoring is consistent with the finite element analysis results, which verifies the reasonableness of the sensor arrangement. The stress is more concentrated in the area of the gate shaft column, the middle door seam, and the rear flange plate during the operation of the miter gate, and the maximum stress appears on the central sector shaft column of the gate. The cracks of the miter gate mainly appeared in the lower layer of the gate body, and the cracks expand gradually during the long-term operation of the gate. The crack expansion speed corresponds to the miter gate’s stress magnitude.

In large ports, shipyards, and other places of handling operations, gantry cranes are widely used. As a typical slewing crane, its slewing-bearing large gear ring is prone to tooth breakage problems due to the existence of long-term complex alternating load. This paper presents a new fault analysis method based on the gear position accuracy error. Firstly, the relative displacement relationship between the pinion and large gear ring and the large gear ring gear teeth stress nature were analyzed through the establishment of the rotary table structure, slewing bearing, and cylinder structure assembly finite element model. In addition, a dynamic data acquisition instrument and resistance strain gauge data were separately applied to analyze the pinion and large gear ring displacement along with cylinder structure stress for the test position accuracy error. The final results show that under the frontal load condition, the horizontal displacement deviation of the pinion gear and the large gear ring is approximately 2.9 mm, which leads to an increase of 23% in the stress value of the upper tooth root at the engagement of the large gear ring, causing extrusion and accelerating the fatigue and even fracture of the gear teeth.

Gear meshing stiffness is one of the important causes of noise, and the structure optimization of gears, such as spoke hole structures, has been proven to be an effective method to reduce gear meshing noise. In this paper, the meshing dynamics model of spur gears with spoke structures was established, and the quasi-static dynamics simulation of the meshing process was carried out by ANSYS. The results show that more spoke holes lead to less meshing stiffness and less stiffness fluctuation. The BEM (boundary element method) acoustic simulation of spur gears meshing was accomplished by the LMS Virtual.Lab. It shows that meshing stiffness is the dominate factor for noise and less meshing stiffness will result in louder noise. In summary, having fewer spoke holes causes less noise, and the experiment shows the same trend. This has certain reference significance for gear structure design considering NVH (noise vibration harshness) performance.