Design and analysis of longitudinal–flexural hybrid transducer for ultrasonic peen forming  

作　　者：Wuqin Li Yongyong Zhu Xiaolong Lu Huafeng Li Ying Wei Pengwei Shang Bo Feng 

机构地区：[1]State Key Laboratory of Mechanics and Control for Aerospace Structures,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China [2]Institute of Dynamics and Vibration Research,Leibniz Universität Hannover,An der Universität 1,Garbsen 30823,Germany

出　　处：《Nanotechnology and Precision Engineering》2023年第4期30-39,共10页纳米技术与精密工程（英文）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.51975278 and 52277055);the Qing Lan Project,the Research Fund of the State Key Laboratory of Mechanics and Control of Mechanical Structures(Nanjing University of Aeronautics and Astronautics)under Grant No.MCMS-I-0321G01;the Biomedical Engineering Fusion Laboratory of the affiliated Jiangning Hospital of Nanjing Medical University(Grant No.JNYYZXKY202217);the Postgraduate Research&Practice Innovation Program of NUAA(Grant Nos.xcxjh20220114 and xcxjh20220111);the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX23_0353).

摘　　要：Ultrasonic peen forming(UPF)is an emerging technology that exhibits great superiority in both its flexible operating modes and the deep residual stress that it produces compared with conventional plastic forming methods.Although ultrasonic transducers with longitudinal vibration have been widely studied,they have seldom been incorporated into UPF devices for machining in confined spaces.To meet the requirements of this type of machining,a sandwich-type piezoelectric transducer with coupled longitudinal-flexural vibrational modes is proposed.The basic structure of the transducer is designed to obtain large vibrational amplitudes in both modes.Experimental results obtained with a prototype device demonstrate the feasibility of the proposed transducer.The measured vibrational amplitude for the working face in the longitudinal vibrational mode is 1.0μm,and electrical matching increases this amplitude by 40%.The flexural vibration characteristics of the same prototype transducer are also tested and are found to be slightly smaller than those of longitudinal mode.The resultant working strokes of the UPF impact pins reach 1.7 mm and 1.2 mm in the longitudinal and flexural modes,respectively.The forming capability of the prototype has been evaluated via 15-min machining on standard 2024-T351 aluminum plates.After UPF,an improved surface morphology with lower surface roughness is obtained.The aluminum plate test piece has an apparent upper deformation with an arc height of 0.64 mm.The measured peak value of the compressive residual stress is around 250 MPa,appearing at a depth of 100μm.The proposed longitudinal-flexural hybrid transducer thus provides a high-performance tool for plate peen forming in confined spaces.

关 键 词：Ultrasonic peen forming Piezoelectric transducer Longitudinal-flexural vibrational mode Modal analysis 

分 类 号：TB552[理学—物理]