Influence Of Excitation Area On Vibration Characteristics Of Curved Pattern Of Curved Rectangular Plate

The compound transducer consisting of a longitudinal vibration transducer and front-end bending vibration radiator is widely used in high power ultrasonic field. The bending vibration radiator are common round and rectangular plate. More research has been focused radiator in the round plate type radiator, and of rectangular plate type radiator less research. On the one hand free boundary condition equation of vibration of rectangular plate bending vibration mode without analytic solution; on the other hand the bending of rectangular plate is more complex than the disk vibration. The model lines of rectangular plate in two directions, and some model lines is bent, some model lines is linear, the law of rectangular plate vibration is complexed.In the rectangular plate radiator, the vibration mode of model lines only parallel to the long edge or the wide edge of the rectangular plate is called the stripe mode of flexural vibration rectangular plate.The model lines of stripe mode is straight, the past research on the stripe modal is less. This paper.the stripe modal pitch lines with the variation of the aspect ratio of the rectangular plate, compared to summarize the characteristics of each rectangular plate bending vibration radiator and radiator striped disk modes. Longitudinal vibration transducer excitation rectangular plate radiator center, in the previous literature, generally regarded as the longitudinal vibration transducer excitation source point. Practical application, especially in high power applications, a certain area of contact between the two will affect the size of the contact area of the vibration characteristics of a rectangular plate radiator. In this paper, the practical application of the existence of this problem, the effects of vibration source area of the rectangular plate stripe modal vibration characteristics.The extent consistent with the definition of thin, rectangular plate thickness has little effect on its vibration modes can be ignored. Than the thickness of the lines of the rectangular plate of our research radiator within the scope of the definition of the sheet, ie modal rectangular plate radiator is only concerned with the aspect ratio of the rectangular plate. Study clearly rectangular plate with striped modal variation of the aspect ratio, can help us design a rectangular plate radiator section line straight stripes use modal. In this paper, the finite element numerical method to calculate the length of one side of the rectangular plate constant, changing the length of the other side, the aspect ratio is increased from0.6to4.0followed by a group of35rectangular plate, the frequency in the range of all stripes modal. Summarizes the stripe modal with the variation of the aspect ratio of the rectangular plate. Calculated from the time the excitation source radius increases, the rectangular plate striped modal vibration mode and vibration displacement. The actual processing of the three rectangular plates of different aspect ratios and different excitation source area of the transducer, using a laser vibrometer (PSV-400) test modes, the board area of a rectangular plate under different excitation modes stripes section line and finite element numerical calculation results were compared, get some conclusions. Details are as follows:1、A study of the laws of the fundamental mode vibration type and stripe pattern rectangular plate radiator. By not changing the length of a rectangular plate shorter side of the radiator, the aspect ratio from0.6to4.0. the stripe pattern was studied Modal variation of the radiator plate with a rectangular aspect ratio. Summary to get a fixed stripe Modal within a certain percentage range in a rectangular plate consecutive:a rectangular plate will be some order of successive stripes vibration mode:and vibration section line parallel to the long side of the (m.0) stripe pattern appears relatively vibration mode of the vibration is parallel to the pitch line broadside (0. n) mode vibration mode stripe appears relatively larger.2、In the set of rectangular plate, the effects of the vibration frequency increases with the variation of the aspect ratio of the rectangular plate radiator. Found that for (m.0) stripe pattern vibration mode frequency decreases with increasing aspect ratio; the (0. n) stripe pattern vibration mode frequency is substantially increased with the aspect ratio big changes. Rectangular plate striped patterns of vibration and the size of the order m of the size of n with a certain frequency there is no relationship between the number of high-order vibration modes are not necessarily greater than the vibration frequency of the vibration of low order modes.3、Compared to the shape, and amplitude of the vibration type disk-type radiator and the radiator of a rectangular plate, the disk was found in appearance is simple, and relatively complex shape of a rectangular plate, the sound field control factors more aspect ratio different rectangular plate, the same stripe modal vibration modes will vary, but the disc of the same modal vibration mode unchanged. When the amplitude of vibration of a rectangular plate bent distributed more evenly than in the disc.4、The influence of the excitation source area of the rectangular plate radiator stripes and vibration mode shapes of displacement. Found on the excitation area of type (m,0) and mode stripe pattern (0,n) modal stripe pattern on the (m.0) stripe pattern modal greater impact; pair (m,0) stripe pattern rectangular plate affect modal vibration section of rectangular plates even and odd lines of the vibration section line is different. Greater impact on the odd-numbered lines of the vibration section.5、Using a laser vibrometer experiment tested under three different excitation modes area of the rectangular plate, pitch line distribution, and with the finite element results were compared with the calculated results agree well.