# Characteristics of Plane Gate Vibration and Holding Force in Closing Process by Experiments
## 3 Results and Discussion
### Correlation between Gate Vibration and Holding Force
#### 3.3.2 Correlation in Closing Process  
Table 5 describes the correlation and significance test between gate vibration and holding force in closing process. The results of significance test indicate a significant correlation between gate vibration and holding force. The correlation coefficient is different for different stages. To be specific, in the initial stage correlation coefficient in three directions is relatively small and the correlation is weak, indicating that gate vibration has a little influence on the holding force and can be ignored for calculating the hoists capacity. In the transitional stage, the average of correlation coefficient in lateral, vertical and horizontal direction is \(-0.565\), \(0.944\) and \(-0.764\), respectively. According to the correlation coefficient from large to small, they were ordered as: vertical \(>\) horizontal \(>\) lateral. Subsequently, in the crawl stage, the average of correlation coefficient in lateral, vertical and horizontal direction is \(-0.723\), \(0.733\) and \(-0.664\), respectively. The correlation coefficient from large to small was as follows: vertical \(>\) lateral \(>\) horizontal. Furthermore, in the transitional and crawl stage, holding force is positively correlated with the vertical vibration and is negatively correlated with the lateral and horizontal vibrations yet. It seems that gate motion state can account for the difference. In the transitional stage, the gate keeps falling and the vertical vibration is directly represented in the holding force. On the basis of the [PERSON]'s second law, there is a liner relationship between gate vibration and holding force. Thus, the correlation is significantly positive, and its coefficient can reach \(0.944\). In the crawl stage, because the gate is in a state of intermittent motion, correlation coefficient is \(0.733\) and smaller than the transitional stage. Meanwhile, lateral and horizontal vibrations make the friction force originating from the seal pressure and panel thrust increase. Thus, the correlation coefficient is negative, and the vibration has a mitigating effect on the holding force. In contrast, if the gate is in an opening process, lateral and horizontal vibrations can increase the holding force and the correlation coefficient should be positive. In summary, the gate vibration effect on the holding force in closing process should be considered in determining the hoists capacity. In addition, we concentrate only on the integral gate vibration as a rigid body in closing process. The limitation of this study is not to consider the horizontal deformation of gate itself in closing process. [PERSON] et al. [36] replaced the circular-arc plate with a vertical, flat, rigid weir-plate and analyzed the rotational vibration along the weir-plate surface through the potential flow theory. The simplification of curved gate manifested that gate vibration was different at different gate heights in fixed gate opening. [PERSON] et al. [29] also found vibration displacement at the bottom of plane gate was greater