Abstract: Structural sound intensity vector diagrams present directly and visually the energy distribution and propagation of the points on shells surface. First of all, the formula for calculating structural sound intensity in local coordinate systems is deduced. By using coordinate transformation, the expression of the structural sound intensity in the global coordinate system is obtained. The sound intensity of a composite shell structure is calculated using FEM, and the sound intensity diagrams are obtained. The results show that the FEM used in this paper is very effective for analysis of the sound intensities of shell structures.

Key words: vibration and wave, structural sound intensity, vibration control, finite element, power flow, coordinate transformation

摘要： 结构声强矢量图直观地给出了壳体表面各点能量传输的分布特性。首先推导了壳体局部坐标下的结构声强计算公式，应用坐标转换得到了结构声强的全局坐标表达式，用有限元计算了筒体和板壳组合结构的结构声强，并绘制出了矢量图。结果表明用有限元法对各种壳体的结构声强进行分析是十分有效的。

关键词: 振动与波, 结构声强, 有限元, 功率流, 坐标变换