指向性是描述声场特性的一个重要指标.因中厚盘弯曲振动的解析解难以得到,数值计算了3种边界条件下弯振厚圆盘基频振动下的辐射声场指向性.计算结果表明,对几何尺寸相同的厚圆盘,在基频振动模式下,固定边界下弯振厚圆盘辐射声场指向性最尖锐,简支居中,自由边界盘的辐射声场只有旁瓣,没有主瓣,指向性不好.与线度相同的薄圆盘相比,厚圆盘的指向性更加尖锐.
Directivity pattern is one of the key indicators describing the radiated acoustic field.The displacement of flexural vibration of a thick plate is difficulty to obtain through the analysis solution.The directivity pattern of a thick plate with fundamental frequency at its flexural vibration has been calculated through numerical calculation.The results show that in terms of its fundamental frequency vibration mode,the directivity pattern with clamped boundary is the best,simply-supported better,while free boundary the poorest.In comparison with the thin plate,the directivity pattern of the thick plate is more acute.