Torque Online Monitoring And Fatigue Life Prediction Software Development Of Main Drive Shaft Of Hot Rolling Mill

The rolling mill is one of the core equipment of the hot rolling production line,and the main drive shaft is an important transmission component for the motor to transmit torque to the roll.Under actual working conditions,the main drive shaft will bear a relatively high level of alternating load,and torsional vibration occurs during the process of biting and throwing steel,which will aggravate the fatigue damage of the main drive shaft.If the main drive shaft breaks,it will cause downtime and stop production,and the workblank will be scrapped.In severe cases,it will threaten the safety of personnel.At this stage,the maintenance strategy for the main drive shaft is generally post-maintenance,that is,repair and replacement when damage occurs.Although this is simple to maintain,the damage has already occurred.At present,the online monitoring of equipment in large domestic steel companies generally uses the online monitoring system provided by large foreign equipment manufacturers,which is expensive to maintain.There is no online monitoring system and life prediction software suitable for the torque of domestic steel companies’ drive shaft.That is not conducive to the maintenance personnel to control the torque load information in the production process in real time and make timely maintenance decisions.In view of the above problems in the maintenance of the main drive shaft,based on the online monitoring technology and fatigue life prediction theory,this paper designs a set of online torque monitoring system for the main drive shaft of the hot rolling mill,and develops a supporting software for main drive shaft.Drive shaft fatigue life prediction software is used to monitor the torque load status of the main drive shaft in real time,analyze the fatigue damage caused by torsional vibration and other loads,and estimate the remaining fatigue life.The main research contents and conclusions of the thesis are as follows:1)Based on the actual torque signal collected on site,the working conditions of the main drive shaft are analyzed,and the characteristics of the torque load reciprocating cycle are discussed;based on information technology,the online torque monitoring system is designed,using B/S as the network architecture of the system,using the torque telemetry system as the physical signal acquisition tool,using multiple applications such as fatigue life prediction software as the signal processing tool,and using Kafka as the high-speed data bus to integrate the subsystems and the total intelligent workshop system,and finally,the analysis results are displayed on the Web.2)According to the torque load characteristics obtained from the analysis of working conditions,using C++and Qt as the development language and framework,the overall design of the fatigue life prediction software is carried out;the software uses frequency domain filtering to remove the signal noise,and the important characteristics parameters of the torque are calculated;the rain flow counting method is used to count the load cycles,and finally,combined with the S-N curve and the shaft abstract model,the nominal stress method is used to predict the remaining fatigue life.3)Use Qt for GUI development,set custom analysis options,improve the ease of use and versatility of the software;open up multiple threads for analysis to ensure the real-time performance of online analysis;use the OOP method for coding,provides an interface for the expansion of subsequent theoretical algorithms;for the difficult problem of C++ resource management,the RAII principle is adopted for development to avoid problems such as resource leak.4)Use Valgrind to check and correct the memory leak of the program;use the historical data collected on site to verify the correctness of the software signal filtering,load cycle statistical algorithm,etc.,and compare with the analysis results of foreign statistical software to verify the effectiveness of the software’s algorithm.The software is deployed on the edge server of the 2250 hot rolling workshop to test the long-term running capability of the software;after the above test,it is proved that the processing capacity and stability of the software meet the requirements of long-term online running.