Research On Processing Vibration And Optimization In Ultrasonic-assisted Grinding Of Sic_p/Al Thin-wallde Structures

In the field of aerospace, reducing their own structual weight of aircraft and rocketnot only means to reduce the cost of manufacture and launch, but also means to improvethe maneuverability of the aircraft and enhance the ability to carry the payload forlonger-distance continuous flight. Thin-walled structures have the characteristics towithstand a greater load with less material. SiCp/Al composite material is a new type ofmaterial with high strength and stiffness, which makes it meet the requirements of theaerospace well. But this workpiece material is also a typical type difficult to process, themost serious of which is the problem of chatter in the process. So this paper is of greatsignificance in the chatter evaluation and the study of prediction.In order to complete the chatter evaluation and the study of prediction of SiCp/Alcomposite material thin-walled structures, this paper establishes the dynamic models inthe grinding process of the ultrasonic vibration assisted grinding and deduces thecharacteristic equation of the grinding dynamic process. According to the distribution ofcharacteristic roots, this paper also determines the stability of the grinding process，uses Matlab to complete the programming of the drawing of grinding chatter stabilitylobe diagram and verifies the program’s accuracy by using time-domain simulation inMatlab-Simulink grinding chatter.To study grinding chatter of typical thin-walled structures, this paper studies theobtaining of grinding force coefficients and modal parameters by testing grinding forceand taking modal measurement experiments of machine system. Based on the abovetests and experiments, we have completed the drawing of chatter stability lobe map andanalyzed the grinding chatter and provided a theoretical basis for the optimization of theactual processing parameters.To verify the established dynamic model of the ultrasonic vibration assistedgrinding process, this paper designs and completes related experiments whichtransforms the frequency spectrum of the acquired processing vibration signals in thegrinding process and analyzes impact of ultrasonic vibration on grinding chatter stability.In addition, this paper also detects the processed surface morphology and verifies theconsistency between processing surface chatter mark and theoretical predictions. Fromthe above, we can verify the correctness of the modal.For the purpose of improving the processing efficiency and quality of SiCp/Althin-walled structures, with grinding stability and material removal rate as constraintconditions, this paper takes processing tests studying the impact on the surfaceroughness of four grinding parameters including spindle speed, feeding rate, grinding depth and ultrasound amplitude and their primary and secondary relationship. Theabove provides a basis for the optimization of the grinding parameters.