Development Of Thermal Fatigue Simulation Test Bench For Components Based On Laser Heat Source

In the context of the research on the reliability of internal combustion engines,the thermal fatigue simulation test bench has become an increasingly important research method of thermal fatigue test.This project designed and developed a thermal fatigue simulation test bench for verifying a low-speed dual-fuel engine.The development method selected hardware equipment with better performance,compiled more comprehensive software,arranged a more complete parameter acquisition system and test bed monitoring system,and achieved the proposed functional goals.The specific completion contents are as follows:(1)The design of the overall scheme of the test bench,according to the functional objectives and technical indicators of the project,the overall scheme of the test bed was designed,and the system modules were divided according to the functions and other factors,and the system modules were defined.(2)According to the overall scheme design,the hardware design scheme is completed,and the main methods of controlling acquisition system,mechanical system,safety assurance system,crack identification system,heating system and cooling system are realized by simplification calculation,scaling and finite element simulation.The hardware performs selection calculation,hardware communication interface analysis,summarizes the communication requirements analysis table,and prepares the signal planning for software programming.(3)According to the general scheme design and the general method of software development,the software design scheme is designed.The layered mode is used as the control software architecture,and the software is divided into mutually coupled modules to realize their respective functions and verify the function.Finally,the sub-functions and sub-actions of each functional module are split and combined to realize the business logic of the entire software.(4)For the first time,the machine learning method was introduced into the thermal fatigue simulation test bench.The feature extraction method of BOW-HOG was used to realize the crack recognition function.After analyzing the shortcomings of this method,two improvements and improvements were proposed.The post-crack identification algorithm has higher accuracy and adaptability,and the local optimum of the algorithm parameters is obtained on the defined set.(5)The test bench was integrated and debugged.From the perspective of safety and ease of use,suggestions were made for the integration of the test bench control cabinet.The laser humidity alarm problem was solved,the thermocouple measurement accuracy was calibrated and analyzed,and the test bench temperature was finally completed.The control mode test and the time control mode test obtained the temperature curve of the measuring point and the surface temperature of the test piece,which verified the integrity of the functions of the test bench.