Numerical Simulation And Experimental Studies Of Elastic Plastic Behavior In Water Cavitation Peening Processing

Water cavitation peening (WCP) technology is a new surface strengtheningtreatment technology, which caused the extensive concern of many scholars in thefield of metal surface modification by depending on their own characteristics andadvantages. Its working principle is the reasonable use submerged type high speedhigh pressure water jet cavitation to form a tiny empty bubble group. Empty bubblegroup in solid near the border while breaking up can produce on the shock wave GPapressure, using the pressure to strengthen metal materials. The present study resultshave proved that the technology can form compressive residual stress layer in metalparts of near surface like other shot peening technology, at the same time improve themicrostructure, and thus improve the fatigue life of parts. So many studies focused onthe technology induced compressive residual stress and fatigue strength improvementin the process, but for its cavitation behavior and reinforcement mechanism in theprocess of basic theoretical research is relatively weak, which hindered the furtherdevelopment and perfection of the technology devices. In order to study strengtheningtheory of WCP, elastic-plastic behavior is simulated and experimented in watercavitation peening processing, the main work content is as follows:From the theoretical study of WCP, phenomenon of cavitation is analyzed.Dynamic response, mechanism of residual stress field and the mechanism of plasticdeformation behavior are discussed. Therefore, some main factors of affect theresidual stress and plastic deformation behavior in water cavitation peeningprocessing obtained.Residual stress field and plastic deformation behavior induced by WCP aresimulated by using the finite element software ANSYS/LS-DYNA, pay attention tostudy the technological parameters of shot peening (shock pressure peak and durationof shock pressure and impact times, etc.) on the residual stress field distribution ofsheet and sheet bending deformation characteristics, obtain the basic law of residualstress field distribution of sheet metal and sheet metal under different parameters, andobtain the basic law of residual stress field distribution and plastic deformationbehavior with different parameters.Residual stress field and plastic deformation behavior of water cavitationpeening processing are proved by using X-ray diffraction method and the arc heightmeasuring instrument. Simulation conclusions are agreed with experimental results. Itshows that finite element method can better predict sheet deformation shape and thedistribution of residual stress field of water cavitation peening processing. The gainedconclusions have great significance for the purpose of optimizing the processingparameters of WCP.