纵振激振面积对条纹振动矩形板声场指向性的影响  

Effect of longitudinal vibration excitation source area on radiated acoustic field directivity pattern of stripe vibration mode rectangular plate

作　　者：刘豆豆[1] 贺西平[1] 李家星[1] 

机构地区：[1]陕西师范大学物理学与信息技术学院,陕西西安710119

出　　处：《陕西师范大学学报（自然科学版）》2016年第3期38-42,48,共6页Journal of Shaanxi Normal University：Natural Science Edition

基　　金：国家自然科学基金(11374201)

摘　　要：在大功率超声应用中,纵振激振换能器与阶梯板间有一定接触面积,导致振动节线与凸台边缘不重合。利用数值计算和有限元分析相结合的方法,研究了(8,0)条纹振动模式下激振源面积大小对矩形板声场指向性的影响。结果表明,对尺寸为180mm×120mm×5mm(长×宽×厚)的矩形薄板,随着激振源半径增大,条纹振动节线逐渐弯曲,(8,0)模态共振频率增大,指向性尖锐程度减小。当观察平面垂直于矩形板表面时,沿y轴方向指向性更为尖锐。当半径增大到12 mm时,副瓣已明显出现,故对该矩形板,应选择激振源半径在8mm以内。The connection between the rectangular plat and the longitudinal vibration transducer always has a certain contact area in high-power applications.Thus the deformed nodal line of stripe vibration mode don′t coincide with the expected step edge positions.Using combination of the method of numerical calculation and finite element,the influence of the excitation area on the directivity pattern in（8,0）stripe mode flexural vibration is investigated.The result shows that,for the 180×120×5mm（length×width×thickness）rectangular plate,the nodal lines deform gradually with the increasing of excitation area.The（8,0）modal resonance frequency increases.The directivity pattern becomes less sharply and the acoustic field directivity pattern along the y axis is sharper than that along the xaxis.When the radius of the excitation area increases to 12 mm,the side lobe is obvious.The radius of the excitation area should not be greater than 8mm for the stepped plate.

关 键 词：有限元法 矩形板 激振源面积 节线 指向性 

分 类 号：O426.1[理学—声学]