PSI - Issue 41

Wei Song et al. / Procedia Structural Integrity 41 (2022) 486–491 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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compressor structures and internal components of air conditions are presented in Fig. 1. During the working processing of the compressor, the valve plate opens and closes continuously. When the valve plate is opened, it will hit the baffle at a high speed (the baffle plate is used to limit the lift of the valve plate). During the closing processing of the valve plate, it will impact the valve seat at a high speed. Thus, the valve plate is critical for the saft service of the compressor structures. 2.2. Experimental details The bending fatigue test was carried out on some specimens by fatigue testing machine. Fig. 2(a) shows the extracted specimen direction and geometric scheme for bending fatigue tests. The orientation of the extracted specimens was paralleled and vertical with the direction of rolling direction. Each specimen was manufactured into the shape of rectangle. During the bending fatigue test, the concentrated force F is loaded on one side of the specimens during the bending fatigue test with the fixed constraint on other fixed side. The corresponding deflection is defined as the δm, w hich is presented in Fig. 2(b). The ultrasonic fatigue test system for cantilever beam bending shock vibration was shown in Fig. 2(c). It should be noted that the small deformation caused by the force F can be ignored. Thus, the amplitude of δa contact end was provided by the ultrasound machine. Contact the deflection is the δm ± δa. The deflection angle can maximum stress at the fixed end can be further calculated, which is expressed as the following equation. 澳 m a tan l    + = 澳 (1)

(a)

Fig. 2. (a) Schematic diagram of cantilever bending and geometries of fatigue specimens; (b) The illustration of bending fatigue test; (c) Ultrasonic fatigue test system for cantilever beam bending shock vibration. 2.3. FE model for fatigue mechanical responses To figure out the influence of fatigue loading variability, the beam model was employed to simulate the mechanical response of ultrasonic cyclic bending behaviour. The wire models were chosen to simulate the ultrasonic fatigue test considering the effect of inertial force. The material density was set as 7.7E-09. In the step of creating a section of the beam, the direction of the beam should be determined according to the actual loading condition, which was presented in Fig. 3(a). on the other hand, proceeding in a fatigue manner for the fixed boundary conditions of the beam in one end and bending loading in another side, only deformation of y-direction is allowed for the beam in Fig. 3(b), which is closer to the actual structural behaviour. The side of the beam is subjected to displacement controlled cyclic bending loading in the y-direction. The periodic amplitude is set in ABAQUS. Fig. 2. (a) Schematic diagram of cantilever bending and geometries of fatigue specimens; (b) The