Research On Safety Assessment Method Of Crane Connection Structure Based On Online Modal Parameter Identification

With the rapid development of industry and infrastructure construction,China has become the country with the largest amount of cranes in the world.At the same time,the accident and death rate of cranes are the highest among all special equipment.It is of great significance to monitor the operation state of the cranes in real time so as to ensure the safe operation.On the other hand,bolt structure is the most common connection in mechanical engineering.Therefore,the bolt structure of crane is studied and the safety assessment method of crane connection structure based on online modal parameter identification is proposed in this paper.Firstly,to solve the problem of matrix irreversibility and problem of calculation in timedomain modal parameter estimation method,an improved complex estimation method based on quantum genetic algorithm is proposed.Compared with traditional methods,the improved method can achieve higher recognition accuracy in high white noise environment.Secondly,safety assessment method of crane connection structure is studied.Based on structural modal parameters,an improved safety assessment method is proposed.Additionally,safety assessment test for a crane model was carried out.Experimental results show that the improved safety assessment method can achieve an accurate safety state assessment of the crane connection structure,and it is more accurate and more effective than the traditional method.Thirdly,online monitoring system of crane is studied.For the purpose of online health monitoring of crane,an online health monitoring system of crane is designed.The monitoring system consists of data acquisition system,remote server and data monitoring app system.Finally,based on the improved TOPSIS Model and the improved complex estimation method of modal parameters,the online health monitoring system of crane is applied in the field.The results show that the hardware data acquisition system can collect acceleration signals in X,Y and Z directions during the operation of the crane,and the collected data can be sent to the upper computer system for analysis and processing through 4G network.During operation process of the crane,the safety evaluation result of the crane connection structure is consistent with the actual observation,which verifies the effectiveness and accuracy of the system.